Goginava, Ushangi Almost everywhere divergence of Cesàro means with varying parameters of Walsh-Fourier series. (English) Zbl 1526.42005 J. Math. Anal. Appl. 529, No. 2, Article ID 127153, 9 p. (2024). MSC: 42A20 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, J. Math. Anal. Appl. 529, No. 2, Article ID 127153, 9 p. (2024; Zbl 1526.42005) Full Text: DOI
Gát, György; Goginava, Ushangi Cesáro means with varying parameters of Walsh-Fourier series. (English) Zbl 07745852 Period. Math. Hung. 87, No. 1, 57-74 (2023). MSC: 42C10 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, Period. Math. Hung. 87, No. 1, 57--74 (2023; Zbl 07745852) Full Text: DOI
Goginava, Ushangi; Nagy, Károly Two-dimensional martingale transforms and their applications in summability of Walsh-Fourier series. (English) Zbl 1517.42027 J. Geom. Anal. 33, No. 8, Paper No. 245, 19 p. (2023). MSC: 42C10 42B08 60G46 60G42 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, J. Geom. Anal. 33, No. 8, Paper No. 245, 19 p. (2023; Zbl 1517.42027) Full Text: DOI
Goginava, Ushangi; Nagy, Károly Some properties of the Walsh-Nörlund means. (English) Zbl 1514.42033 Quaest. Math. 46, No. 2, 301-334 (2023). Reviewer: Ghanshyam Bhatt (Nashville) MSC: 42C10 42A20 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Quaest. Math. 46, No. 2, 301--334 (2023; Zbl 1514.42033) Full Text: DOI
Goginava, U. Maximal operators of Walsh-Nörlund means on the dyadic Hardy spaces. (English) Zbl 07672144 Acta Math. Hung. 169, No. 1, 171-190 (2023). Reviewer: Joseph Lakey (Las Cruces) MSC: 42C10 42A16 42A85 46E30 PDFBibTeX XMLCite \textit{U. Goginava}, Acta Math. Hung. 169, No. 1, 171--190 (2023; Zbl 07672144) Full Text: DOI arXiv
Goginava, Ushangi; Nagy, Károly Strong summability of double Vilenkin-Fourier series. (English) Zbl 07672126 Acta Sci. Math. 88, No. 3-4, 673-696 (2022). Reviewer: Joseph Lakey (Las Cruces) MSC: 42C10 46E30 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Acta Sci. Math. 88, No. 3--4, 673--696 (2022; Zbl 07672126) Full Text: DOI
Gát, G.; Goginava, U. The Walsh-Fourier transform on the real line. (English) Zbl 1506.42037 J. Contemp. Math. Anal., Armen. Acad. Sci. 57, No. 4, 205-214 (2022) and Izv. Nats. Akad. Nauk Armen., Mat. 57, No. 4, 3-13 (2022). Reviewer: Wilfredo Urbina (Chicago) MSC: 42C10 42A38 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, J. Contemp. Math. Anal., Armen. Acad. Sci. 57, No. 4, 205--214 (2022; Zbl 1506.42037) Full Text: DOI
Gát, György; Goginava, Ushangi Almost everywhere convergence and divergence of Cesàro means with varying parameters of Walsh-Fourier series. (English) Zbl 1496.42038 Arab. J. Math. 11, No. 2, 241-259 (2022). Reviewer: Iris Athamaica Lopez Palacios (Caracas) MSC: 42C10 42A20 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, Arab. J. Math. 11, No. 2, 241--259 (2022; Zbl 1496.42038) Full Text: DOI
Goginava, Ushangi Almost everywhere summability of two-dimensional Walsh-Fourier series. (English) Zbl 1500.42013 Positivity 26, No. 4, Paper No. 63, 22 p. (2022). Reviewer: Giorgi Oniani (Kutaisi) MSC: 42C10 42A24 40G05 PDFBibTeX XMLCite \textit{U. Goginava}, Positivity 26, No. 4, Paper No. 63, 22 p. (2022; Zbl 1500.42013) Full Text: DOI
Goginava, U.; Saatashvili, A. Conjugate transforms on dyadic group. (English) Zbl 1465.42027 J. Contemp. Math. Anal., Armen. Acad. Sci. 56, No. 1, 9-22 (2021) and Izv. Nats. Akad. Nauk Armen., Mat. 56, No. 1, 16-34 (2021). MSC: 42C10 60G42 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{A. Saatashvili}, J. Contemp. Math. Anal., Armen. Acad. Sci. 56, No. 1, 9--22 (2021; Zbl 1465.42027) Full Text: DOI arXiv
Goginava, Ushangi; Said, Salem Ben Convergence in measure of Fejér means of two parameter conjugate Walsh transforms. (English) Zbl 1465.42028 Math. Inequal. Appl. 24, No. 1, 115-128 (2021). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{S. B. Said}, Math. Inequal. Appl. 24, No. 1, 115--128 (2021; Zbl 1465.42028) Full Text: DOI
Goginava, Ushangi; Oniani, Giorgi On the divergence of subsequences of partial Walsh-Fourier sums. (English) Zbl 1479.42008 J. Math. Anal. Appl. 497, No. 2, Article ID 124900, 14 p. (2021). Reviewer: Miroslav Repický (Košice) MSC: 42A20 42C10 40A30 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{G. Oniani}, J. Math. Anal. Appl. 497, No. 2, Article ID 124900, 14 p. (2021; Zbl 1479.42008) Full Text: DOI arXiv
Goginava, Ushangi; Oniani, Giorgi On the almost everywhere convergence of multiple Fourier series of square summable functions. (English) Zbl 1488.42048 Publ. Math. Debr. 97, No. 3-4, 313-320 (2020). Reviewer: Alexander Ulanovskii (Stavanger) MSC: 42B05 42A55 42C10 26D15 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{G. Oniani}, Publ. Math. Debr. 97, No. 3--4, 313--320 (2020; Zbl 1488.42048) Full Text: DOI
Gát, G.; Goginava, U. Pointwise strong summability of Vilenkin-Fourier series. (English) Zbl 1451.42006 Math. Notes 108, No. 4, 499-510 (2020). MSC: 42A20 22A99 42C10 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, Math. Notes 108, No. 4, 499--510 (2020; Zbl 1451.42006) Full Text: DOI
Goginava, Ushangi Subsequences of spherical sums of double Walsh-Fourier series. (English) Zbl 1443.42017 Nonlinear Stud. 26, No. 4, 821-830 (2019). MSC: 42C10 42A20 42A55 PDFBibTeX XMLCite \textit{U. Goginava}, Nonlinear Stud. 26, No. 4, 821--830 (2019; Zbl 1443.42017) Full Text: Link
Goginava, U. Strong summability of two-dimensional Vilenkin-Fourier series. (English) Zbl 1434.42005 Ukr. Math. J. 71, No. 3, 387-401 (2019) and Ukr. Mat. Zh. 71, No. 3, 340-352 (2019). MSC: 42A24 42C10 42A10 PDFBibTeX XMLCite \textit{U. Goginava}, Ukr. Math. J. 71, No. 3, 387--401 (2019; Zbl 1434.42005) Full Text: DOI arXiv
Gát, Gyorgy; Goginava, U. Convergence of a subsequence of triangular partial sums of double Walsh-Fourier series. (English) Zbl 1431.42050 J. Contemp. Math. Anal., Armen. Acad. Sci. 54, No. 4, 210-215 (2019) and Izv. Nats. Akad. Nauk Armen., Mat. 54, No. 4, 3-11 (2019). MSC: 42C10 42C05 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, J. Contemp. Math. Anal., Armen. Acad. Sci. 54, No. 4, 210--215 (2019; Zbl 1431.42050) Full Text: DOI
Gát, Gy.; Goginava, U. Maximal operators of Cesáro means with varying parameters of Walsh-Fourier series. (English) Zbl 1449.42045 Acta Math. Hung. 159, No. 2, 653-668 (2019). Reviewer: Gustaf Gripenberg (Aalto) MSC: 42C10 42B25 PDFBibTeX XMLCite \textit{Gy. Gát} and \textit{U. Goginava}, Acta Math. Hung. 159, No. 2, 653--668 (2019; Zbl 1449.42045) Full Text: DOI
Goginava, Ushangi Logarithmic means of Walsh-Fourier series. (English) Zbl 1438.42053 Miskolc Math. Notes 20, No. 1, 255-270 (2019). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Miskolc Math. Notes 20, No. 1, 255--270 (2019; Zbl 1438.42053) Full Text: DOI arXiv
Gát, Gy.; Goginava, U. Norm convergence of double Fejér means on unbounded Vilenkin groups. (English) Zbl 1438.42052 Anal. Math. 45, No. 1, 39-62 (2019). Reviewer: Joseph Lakey (Las Cruces) MSC: 42C10 PDFBibTeX XMLCite \textit{Gy. Gát} and \textit{U. Goginava}, Anal. Math. 45, No. 1, 39--62 (2019; Zbl 1438.42052) Full Text: DOI
Gát, György; Goginava, Ushangi Subsequences of triangular partial sums of double Fourier series on unbounded Vilenkin groups. (English) Zbl 1499.42125 Filomat 32, No. 11, 3769-3778 (2018). MSC: 42C10 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, Filomat 32, No. 11, 3769--3778 (2018; Zbl 1499.42125) Full Text: DOI
Goginava, U.; Karagulyan, G. On exponential summability of rectangular partial sums of double trigonometric Fourier series. (English. Russian original) Zbl 1412.42069 Math. Notes 104, No. 5, 655-665 (2018); translation from Mat. Zametki 104, No. 5, 667-679 (2018). Reviewer: Rostom Getsadze (Uppsala) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{G. Karagulyan}, Math. Notes 104, No. 5, 655--665 (2018; Zbl 1412.42069); translation from Mat. Zametki 104, No. 5, 667--679 (2018) Full Text: DOI arXiv
Goginava, U. Almost everywhere convergence of strong Nörlund logarithmic means of Walsh-Fourier series. (English) Zbl 1414.42033 J. Contemp. Math. Anal., Armen. Acad. Sci. 53, No. 5, 281-287 (2018) and Izv. Nats. Akad. Nauk Armen., Mat. 53, No. 5, 11-21 (2018). Reviewer: Ferenc Weisz (Budapest) MSC: 42C10 42B08 PDFBibTeX XMLCite \textit{U. Goginava}, J. Contemp. Math. Anal., Armen. Acad. Sci. 53, No. 5, 281--287 (2018; Zbl 1414.42033) Full Text: DOI
Goginava, U. Almost everywhere strong summability of Fejér means of rectangular partial sums of two-dimensional Walsh-Fourier series. (English) Zbl 1404.42054 J. Contemp. Math. Anal., Armen. Acad. Sci. 53, No. 2, 100-112 (2018) and Izv. Nats. Akad. Nauk Armen., Mat. 53, No. 2, 31-46 (2018). Reviewer: Ferenc Weisz (Budapest) MSC: 42C10 42B08 PDFBibTeX XMLCite \textit{U. Goginava}, J. Contemp. Math. Anal., Armen. Acad. Sci. 53, No. 2, 100--112 (2018; Zbl 1404.42054) Full Text: DOI arXiv
Gát, György; Goginava, Ushangi Norm convergence of logarithmic means on unbounded Vilenkin groups. (English) Zbl 1394.42019 Banach J. Math. Anal. 12, No. 2, 422-438 (2018). Reviewer: Giorgi Oniani (Kutaisi) MSC: 42C10 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, Banach J. Math. Anal. 12, No. 2, 422--438 (2018; Zbl 1394.42019) Full Text: DOI Euclid
Gát, Gy.; Goginava, U. Almost everywhere convergence of subsequence of quadratic partial sums of two-dimensional Walsh-Fourier series. (English) Zbl 1413.42052 Anal. Math. 44, No. 1, 73-88 (2018). MSC: 42C10 PDFBibTeX XMLCite \textit{Gy. Gát} and \textit{U. Goginava}, Anal. Math. 44, No. 1, 73--88 (2018; Zbl 1413.42052) Full Text: DOI
Gát, Gy.; Goginava, U. Norm convergence of double Fourier series on unbounded Vilenkin groups. (English) Zbl 1399.42075 Acta Math. Hung. 152, No. 1, 201-216 (2017). Reviewer: Alexei Lukashov (Saratov) MSC: 42C10 42B05 PDFBibTeX XMLCite \textit{Gy. Gát} and \textit{U. Goginava}, Acta Math. Hung. 152, No. 1, 201--216 (2017; Zbl 1399.42075) Full Text: DOI
Goginava, U. Pointwise convergence of Marcinkiewicz-Fejér means of double Vilenkin-Fourier series. (English) Zbl 1386.42018 J. Contemp. Math. Anal., Armen. Acad. Sci. 52, No. 5, 242-253 (2017) and Izv. Nats. Akad. Nauk Armen., Mat. 52, No. 5, 36-51 (2017). Reviewer: Shuichi Sato (Kanazawa) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, J. Contemp. Math. Anal., Armen. Acad. Sci. 52, No. 5, 242--253 (2017; Zbl 1386.42018) Full Text: DOI arXiv
Goginava, Ushangi Almost everywhere strong summability of cubic partial sums of d-dimensional Walsh-Fourier series. (English) Zbl 1386.42019 Math. Inequal. Appl. 20, No. 4, 1051-1066 (2017). Reviewer: Giorgi Oniani (Kutaisi) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Math. Inequal. Appl. 20, No. 4, 1051--1066 (2017; Zbl 1386.42019) Full Text: DOI
Goginava, U.; Nagy, K. Strong approximation by Marcinkiewicz means of twodimensional Walsh-Kaczmarz-Fourier series. (English) Zbl 1389.42057 Anal. Math. 42, No. 2, 143-157 (2016). Reviewer: György Gát (Nyíregyháza) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Anal. Math. 42, No. 2, 143--157 (2016; Zbl 1389.42057) Full Text: DOI arXiv
Goginava, Ushangi Almost everywhere strong summability of two-dimensional Walsh-Fourier series. (English) Zbl 1363.42048 Acta Math. Acad. Paedagog. Nyházi. (N.S.) 32, No. 2, 233-246 (2016). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Acta Math. Acad. Paedagog. Nyházi. (N.S.) 32, No. 2, 233--246 (2016; Zbl 1363.42048) Full Text: arXiv
Goginava, Ushangi; Nagy, Karoly Weak type inequality for the maximal operator of Walsh-Kaczmarz-Marcinkiewicz means. (English) Zbl 1363.42031 Acta Math. Sci., Ser. B, Engl. Ed. 36, No. 2, 359-370 (2016). MSC: 42B25 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Acta Math. Sci., Ser. B, Engl. Ed. 36, No. 2, 359--370 (2016; Zbl 1363.42031) Full Text: DOI
Gát, György; Goginava, Ushangi Almost everywhere convergence of dyadic triangular-Fejér means of two-dimensional Walsh-Fourier series. (English) Zbl 1341.42048 Math. Inequal. Appl. 19, No. 2, 401-415 (2016). Reviewer: Jeremy Wade (Eugene) MSC: 42C10 40G05 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, Math. Inequal. Appl. 19, No. 2, 401--415 (2016; Zbl 1341.42048) Full Text: DOI Link
Goginava, U.; Nagy, K. The two-dimensional Fejér means on diagonal Hardy space. (English) Zbl 1363.42047 Period. Math. Hung. 70, No. 2, 248-256 (2015). Reviewer: György Gát (Nyíregyháza) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Period. Math. Hung. 70, No. 2, 248--256 (2015; Zbl 1363.42047) Full Text: DOI
Gát, G.; Goginava, U. Almost everywhere strong summability of double Walsh-Fourier series. (English) Zbl 1329.42028 J. Contemp. Math. Anal., Armen. Acad. Sci. 50, No. 1, 1-13 (2015) and Izv. Nats. Akad. Nauk Armen., Mat. 50, No. 1, 23–40 (2015). MSC: 42C10 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, J. Contemp. Math. Anal., Armen. Acad. Sci. 50, No. 1, 1--13 (2015; Zbl 1329.42028) Full Text: DOI arXiv
Gát, G.; Goginava, U.; Karagulyan, G. On everywhere divergence of the strong \(\Phi\)-means of Walsh-Fourier series. (English) Zbl 1297.42039 J. Math. Anal. Appl. 421, No. 1, 206-214 (2015). MSC: 42C10 40A05 PDFBibTeX XMLCite \textit{G. Gát} et al., J. Math. Anal. Appl. 421, No. 1, 206--214 (2015; Zbl 1297.42039) Full Text: DOI arXiv
Gát, György; Goginava, Ushangi; Karagulyan, Grigori Almost everywhere strong summability of Marcinkiewicz means of double Walsh-Fourier series. (English) Zbl 1340.42066 Anal. Math. 40, No. 4, 243-266 (2014). Reviewer: Ferenc Weisz (Budapest) MSC: 42C10 42B08 PDFBibTeX XMLCite \textit{G. Gát} et al., Anal. Math. 40, No. 4, 243--266 (2014; Zbl 1340.42066)
Goginava, U.; Sahakian, A. A. On the convergence and summability of double Walsh-Fourier series of functions of bounded generalized variation. (English) Zbl 1368.42026 J. Contemp. Math. Anal., Armen. Acad. Sci. 49, No. 6, 321-333 (2014) and Izv. Nats. Akad. Nauk Armen., Mat. 49, No. 6, 51–65 (2014). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{A. A. Sahakian}, J. Contemp. Math. Anal., Armen. Acad. Sci. 49, No. 6, 321--333 (2014; Zbl 1368.42026) Full Text: DOI arXiv
Goginava, Ushangi Uniform summability of double Walsh-Fourier series of functions of bounded partial \(\Lambda \)-variation. (English) Zbl 1349.42058 Math. Slovaca 64, No. 6, 1451-1474 (2014). Reviewer: Artur Sahakian (Yerevan) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Math. Slovaca 64, No. 6, 1451--1474 (2014; Zbl 1349.42058) Full Text: DOI
Gát, G.; Goginava, U.; Karagulyan, G. A remark on the divergence of strong power means of Walsh-Fourier series. (English) Zbl 1316.42033 Math. Notes 96, No. 5, 897-903 (2014). MSC: 42C10 PDFBibTeX XMLCite \textit{G. Gát} et al., Math. Notes 96, No. 5, 897--903 (2014; Zbl 1316.42033) Full Text: DOI
Gogatishvili, Amiran; Goginava, Ushangi; Tephnadze, George Relations between some classes of functions of generalized bounded variation. (English) Zbl 1307.42026 Hudzik, Henryk (ed.) et al., Function spaces X. Proceedings of the 10th international conference, Poznań, Poland, July 9–13, 2012. Warszawa: Polish Academy of Sciences, Institute of Mathematics (ISBN 978-83-86806-25-6/pbk). Banach Center Publications 102, 89-98 (2014). MSC: 42C10 PDFBibTeX XMLCite \textit{A. Gogatishvili} et al., Banach Cent. Publ. 102, 89--98 (2014; Zbl 1307.42026) Full Text: DOI arXiv
Goginava, Ushangi; Gogoladze, Larry A note on strong summability of two-dimensional Walsh-Fourier series. (English) Zbl 1324.42040 Period. Math. Hung. 66, No. 2, 211-219 (2013). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{L. Gogoladze}, Period. Math. Hung. 66, No. 2, 211--219 (2013; Zbl 1324.42040) Full Text: DOI
Goginava, Ushangi; Nagy, Károly On the boundedness of the maximal operators of double Walsh-logarithmic means of Marcinkiewicz type. (English) Zbl 1340.42067 Math. Slovaca 63, No. 4, 839-848 (2013). Reviewer: György Gát (Nyiregyháza) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Math. Slovaca 63, No. 4, 839--848 (2013; Zbl 1340.42067) Full Text: DOI
Nagy, Károly; Goginava, Ushangi Maximal operators of Walsh-Kaczmarz logarithmic means. (English) Zbl 1290.42055 Complex Var. Elliptic Equ. 58, No. 9, 1173-1182 (2013). Reviewer: Karen Keryan (Yerevan) MSC: 42C10 42B25 PDFBibTeX XMLCite \textit{K. Nagy} and \textit{U. Goginava}, Complex Var. Elliptic Equ. 58, No. 9, 1173--1182 (2013; Zbl 1290.42055) Full Text: DOI
Goginava, Ushangi; Gogoladze, Larry Strong convergence of cubic partial sums of two-dimensional Walsh-Fourier series. (English) Zbl 1430.42031 Nikolov, Geno (ed.) et al., Constructive theory of functions. In memory of Borislav Bojanov. Papers from the international conference, Sozopol, Bulgaria, June 3–10, 2010. Sofia: Prof. Marin Drinov Academic Publishing House. 108-117 (2012). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{L. Gogoladze}, in: Constructive theory of functions. In memory of Borislav Bojanov. Papers from the international conference, Sozopol, Bulgaria, June 3--10, 2010. Sofia: Prof. Marin Drinov Academic Publishing House. 108--117 (2012; Zbl 1430.42031)
Goginava, Ushangi Uniform convergence of double Fourier-Legendre series of functions of bounded generalized variation. (English) Zbl 1321.42046 Bull. TICMI 16, No. 2, 1-20 (2012). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Bull. TICMI 16, No. 2, 1--20 (2012; Zbl 1321.42046) Full Text: arXiv EMIS
Goginava, U.; Sahakian, A. On the convergence of multiple Walsh-Fourier series of functions of bounded generalized variation. (English) Zbl 1273.42029 J. Contemp. Math. Anal., Armen. Acad. Sci. 47, No. 5, 221-233 (2012) and Izv. Nats. Akad. Nauk Armen., Mat. 47, No. 5, 21-38 (2012). Reviewer: Enji Sato (Yamagata) MSC: 42C10 42C05 42C40 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{A. Sahakian}, J. Contemp. Math. Anal., Armen. Acad. Sci. 47, No. 5, 221--233 (2012; Zbl 1273.42029) Full Text: DOI
Goginava, Ushangi; Weisz, Ferenc Pointwise convergence of Marcinkiewicz-Fejér means of two-dimensional Walsh-Fourier series. (English) Zbl 1274.42070 Stud. Sci. Math. Hung. 49, No. 2, 236-253 (2012). Reviewer: István Mező (Quito) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{F. Weisz}, Stud. Sci. Math. Hung. 49, No. 2, 236--253 (2012; Zbl 1274.42070) Full Text: DOI
Goginava, Ushangi; Gogoladze, Larry Strong approximation of two-dimensional Walsh-Fourier series. (English) Zbl 1274.42069 Stud. Sci. Math. Hung. 49, No. 2, 170-188 (2012). Reviewer: István Mező (Quito) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{L. Gogoladze}, Stud. Sci. Math. Hung. 49, No. 2, 170--188 (2012; Zbl 1274.42069) Full Text: DOI
Goginava, Ushangi; Nagy, Károly Marcinkiewicz-Fejér means of double conjugate Walsh-Kaczmarz-Fourier series and Hardy spaces. (English) Zbl 1250.42083 Turk. J. Math. 36, No. 2, 281-290 (2012). Reviewer: Ferenc Weisz (Budapest) MSC: 42C10 60G42 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Turk. J. Math. 36, No. 2, 281--290 (2012; Zbl 1250.42083)
Goginava, Ushangi; Weisz, Ferenc Maximal operator of the Fejér means of triangular partial sums of two-dimensional Walsh-Fourier series. (English) Zbl 1266.42072 Georgian Math. J. 19, No. 1, 101-115 (2012). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{F. Weisz}, Georgian Math. J. 19, No. 1, 101--115 (2012; Zbl 1266.42072) Full Text: DOI
Goginava, Ushangi; Gogoladze, Larry Strong approximation by Marcinkiewicz means of two-dimensional Walsh-Fourier series. (English) Zbl 1238.42013 Constr. Approx. 35, No. 1, 1-19 (2012). Reviewer: Enji Sato (Yamagata) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{L. Gogoladze}, Constr. Approx. 35, No. 1, 1--19 (2012; Zbl 1238.42013) Full Text: DOI
Goginava, Ushangi; Nagy, Károly Convergence in measure of logarithmic means of quadratical partial sums of double Walsh-Kaczmarz-Fourier series. (English) Zbl 1231.42025 J. Funct. Spaces Appl. 2012, Article ID 582726, 15 p. (2012). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, J. Funct. Spaces Appl. 2012, Article ID 582726, 15 p. (2012; Zbl 1231.42025) Full Text: DOI arXiv
Goginava, Ushangi The martingale Hardy type inequality for Marcinkiewicz-Fejér means of two-dimensional conjugate Walsh-Fourier series. (English) Zbl 1282.42026 Acta Math. Sin., Engl. Ser. 27, No. 10, 1949-1958 (2011). Reviewer: Stepan Sargsyan (Yerevan) MSC: 42C10 42B05 42A50 PDFBibTeX XMLCite \textit{U. Goginava}, Acta Math. Sin., Engl. Ser. 27, No. 10, 1949--1958 (2011; Zbl 1282.42026) Full Text: DOI
Goginava, Ushangi The Hardy type inequality for the maximal operator of the one-dimensional dyadic derivative. (English) Zbl 1249.42009 Acta Math. Sci., Ser. B, Engl. Ed. 31, No. 4, 1489-1493 (2011). MSC: 42C10 42B30 PDFBibTeX XMLCite \textit{U. Goginava}, Acta Math. Sci., Ser. B, Engl. Ed. 31, No. 4, 1489--1493 (2011; Zbl 1249.42009) Full Text: DOI
Goginava, Ushangi; Nagy, Károly On the maximal operator of Walsh-Kaczmarz-Fejér means. (English) Zbl 1249.42011 Czech. Math. J. 61, No. 3, 673-686 (2011). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Czech. Math. J. 61, No. 3, 673--686 (2011; Zbl 1249.42011) Full Text: DOI EuDML Link
Goginava, Ushangi Norm convergence of Fejér means of two-dimensional Walsh-Fourier series. (English) Zbl 1246.42023 Nawrocki, Marek (ed.) et al., Marcinkiewicz centenary volume. Proceedings of the Józef Marcinkiewicz centenary conference, June 28–July 2, 2010. Warszawa: Polish Academy of Sciences, Institute of Mathematics (ISBN 978-83-86806-14-0/pbk). Banach Center Publications 95, 317-324 (2011). Reviewer: Ferenc Weisz (Budapest) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Banach Cent. Publ. 95, 317--324 (2011; Zbl 1246.42023) Full Text: DOI
Goginava, Ushangi; Gogoladze, Larry Pointwise summability of Vilenkin-Fourier series. (English) Zbl 1249.42010 Publ. Math. Debr. 79, No. 1-2, 89-108 (2011). Reviewer: István Mező (Debrecen) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{L. Gogoladze}, Publ. Math. Debr. 79, No. 1--2, 89--108 (2011; Zbl 1249.42010) Full Text: DOI
Goginava, U. Weak type inequality for the one-dimensional dyadic derivative. (English) Zbl 1227.42030 Math. Inequal. Appl. 14, No. 4, 839-848 (2011). Reviewer: István Mező (Debrecen) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Math. Inequal. Appl. 14, No. 4, 839--848 (2011; Zbl 1227.42030) Full Text: DOI
Goginava, Ushangi Maximal operators of logarithmic means of one-dimensional Walsh-Fourier series. (English) Zbl 1470.42052 Proceedings of the sixth international conference on functional analysis and approximation theory, Acquafredda di Maratea, Potenza, Italy, September 24–30, 2009. Palermo: Circolo Matematico di Palermo. Suppl. Rend. Circ. Mat. Palermo (2) 82, 345-357 (2010). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Suppl. Rend. Circ. Mat. Palermo (2) 82, 345--357 (2010; Zbl 1470.42052)
Goginava, Ushahgi A note on the Walsh-Fejér means. (English) Zbl 1240.42126 Anal. Theory Appl. 26, No. 4, 320-325 (2010). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Anal. Theory Appl. 26, No. 4, 320--325 (2010; Zbl 1240.42126) Full Text: DOI
Goginava, Ushahgi Maximal operators of Fejér means of Walsh-Fourier series. (English) Zbl 1240.42125 Ann. Univ. Sci. Budap. Rolando Eötvös, Sect. Comput. 33, 193-203 (2010). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Ann. Univ. Sci. Budap. Rolando Eötvös, Sect. Comput. 33, 193--203 (2010; Zbl 1240.42125) Full Text: Link
Blahota, István; Goginava, Ushangi The martingale Hardy type inequality for the maximal operator of the \((C,\alpha)\) means of cubic partial sums of the \(d\)-dimensional conjugate Walsh-Fourier series. (English) Zbl 1240.42123 Math. Pannonica 21, No. 1, 65-76 (2010). MSC: 42C10 PDFBibTeX XMLCite \textit{I. Blahota} and \textit{U. Goginava}, Math. Pannonica 21, No. 1, 65--76 (2010; Zbl 1240.42123)
Goginava, Ushangi Weak type inequalityy for the maximal operator of the \((C,\alpha)\) means of two-dimensional Walsh-Fourier series. (English) Zbl 1240.42127 Anal. Math. 36, No. 1, 1-31 (2010). Reviewer: Ferenc Weisz (Budapest) MSC: 42C10 43A75 60G42 42B30 PDFBibTeX XMLCite \textit{U. Goginava}, Anal. Math. 36, No. 1, 1--31 (2010; Zbl 1240.42127)
Goginava, Ushangi; Nagy, Károly Weak type inequality for logarithmic means of Walsh-Kaczmarz-Fourier series. (English) Zbl 1219.42018 Real Anal. Exch. 35(2009-2010), No. 2, 445-462 (2010). Reviewer: Joseph Lakey (Las Cruces) MSC: 42C10 42B08 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Real Anal. Exch. 35, No. 2, 445--462 (2010; Zbl 1219.42018) Full Text: DOI
Goginava, U.; Nagy, K. On the maximal operator of \((C,\alpha)\)-means of Walsh-Kaczmarz-Fourier series. (English) Zbl 1224.42077 Ukr. Mat. Zh. 62, No. 2, 158-166 (2010) and in Ukr. Math. J. 62, No. 2, 175-185 (2010). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Ukr. Mat. Zh. 62, No. 2, 158--166 (2010; Zbl 1224.42077) Full Text: DOI
Goginava, Ushangi; Nagy, Károly Maximal operators of Fejér means of Walsh-Kaczmarz-Fourier series. (English) Zbl 1194.42034 J. Funct. Spaces Appl. 8, No. 2, 181-200 (2010). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, J. Funct. Spaces Appl. 8, No. 2, 181--200 (2010; Zbl 1194.42034) Full Text: DOI
Gát, György; Goginava, Ushangi; Nagy, Károly On the Marcinkiewicz-Fejér means of double Fourier series with respect to the Walsh-Kaczmarz system. (English) Zbl 1274.42068 Stud. Sci. Math. Hung. 46, No. 3, 399-421 (2009). MSC: 42C10 PDFBibTeX XMLCite \textit{G. Gát} et al., Stud. Sci. Math. Hung. 46, No. 3, 399--421 (2009; Zbl 1274.42068) Full Text: DOI
Goginava, Ushangi Restricted maximal operators of Fejér means of double Walsh-Fourier series. (English) Zbl 1224.42078 Period. Math. Hung. 59, No. 2, 173-183 (2009). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Period. Math. Hung. 59, No. 2, 173--183 (2009; Zbl 1224.42078) Full Text: DOI
Gát, Gy.; Goginava, U. A weak type inequality for the maximal operator of \((C,\alpha)\)-means of Fourier series with respect to the Walsh-Kaczmarz system. (English) Zbl 1212.42072 Acta Math. Hung. 125, No. 1-2, 65-83 (2009). Reviewer: István Mező (Debrecen) MSC: 42C10 PDFBibTeX XMLCite \textit{Gy. Gát} and \textit{U. Goginava}, Acta Math. Hung. 125, No. 1--2, 65--83 (2009; Zbl 1212.42072) Full Text: DOI
Goginava, Ushangi Convergence in measure of partial sums of double Vilenkin-Fourier series. (English) Zbl 1178.42027 Georgian Math. J. 16, No. 3, 507-516 (2009). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Georgian Math. J. 16, No. 3, 507--516 (2009; Zbl 1178.42027)
Goginava, Ushangi; Nagy, Károly On the maximal operator of the Marcinkiewicz-Fejér means of double Walsh-Kaczmarz-Fourier series. (English) Zbl 1212.42073 Publ. Math. Debr. 75, No. 1-2, 95-104 (2009). Reviewer: Vanna Zanelli (Modena) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Publ. Math. Debr. 75, No. 1--2, 95--104 (2009; Zbl 1212.42073)
Gát, György; Goginava, Ushangi On the divergence of Nörlund logarithmic means of Walsh-Fourier series. (English) Zbl 1173.42320 Acta Math. Sin., Engl. Ser. 25, No. 6, 903-916 (2009). MSC: 42C10 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, Acta Math. Sin., Engl. Ser. 25, No. 6, 903--916 (2009; Zbl 1173.42320) Full Text: DOI
Goginava, Ushangi The weak type inequality for the maximal operator of the Marcinkiewicz-Fejér means of the two-dimensional Walsh-Kaczmarz system. (English) Zbl 1172.42010 Math. Inequal. Appl. 12, No. 2, Article ID 19, 227-238 (2009). Reviewer: Boris I. Golubov (Dolgoprudny) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Math. Inequal. Appl. 12, No. 2, Article ID 19, 227--238 (2009; Zbl 1172.42010) Full Text: DOI
Goginava, U. Maximal operators of the Fejér means of the two dimensional character system of the \(p\)-series field in the Kaczmarz rearrangement. (English) Zbl 1199.42126 Acta Math. Univ. Comen., New Ser. 78, No. 1, 53-63 (2009). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Acta Math. Univ. Comen., New Ser. 78, No. 1, 53--63 (2009; Zbl 1199.42126) Full Text: EuDML
Goginava, U. On the divergence of Walsh-Fejér means of bounded functions on sets of measure zero. (English) Zbl 1265.42096 Acta Math. Hung. 121, No. 4, 359-369 (2008). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Acta Math. Hung. 121, No. 4, 359--369 (2008; Zbl 1265.42096) Full Text: DOI
Blahota, István; Goginava, Ushangi The maximal operator of the Marcinkiewicz-Fejér means of the 2-dimensional Vilenkin-Fourier series. (English) Zbl 1199.42123 Stud. Sci. Math. Hung. 45, No. 3, 321-331 (2008). MSC: 42C10 PDFBibTeX XMLCite \textit{I. Blahota} and \textit{U. Goginava}, Stud. Sci. Math. Hung. 45, No. 3, 321--331 (2008; Zbl 1199.42123) Full Text: DOI
Goginava, Ushangi Maximal operators of Fejér-Walsh means. (English) Zbl 1199.42127 Acta Sci. Math. 74, No. 3-4, 615-624 (2008). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Acta Sci. Math. 74, No. 3--4, 615--624 (2008; Zbl 1199.42127)
Goginava, Ushangi Maximal \((C,\alpha,\beta)\) operators of two-dimensional Walsh-Fourier series. (English) Zbl 1164.42320 Acta Math. Acad. Paedagog. Nyházi. (N.S.) 24, No. 2, 209-214 (2008). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Acta Math. Acad. Paedagog. Nyházi. (N.S.) 24, No. 2, 209--214 (2008; Zbl 1164.42320) Full Text: EuDML
Goginava, Ushangi The weak type inequality for the maximal operator of the Marcinkiewicz-Fejér means of the two-dimensional Walsh-Fourier series. (English) Zbl 1183.42028 J. Approx. Theory 154, No. 2, 161-180 (2008). Reviewer: Jörg Wenzel (Kaiserslautern) MSC: 42C10 42B25 PDFBibTeX XMLCite \textit{U. Goginava}, J. Approx. Theory 154, No. 2, 161--180 (2008; Zbl 1183.42028) Full Text: DOI
Goginava, Ushangi; Nagy, Károly On the Marcinkiewicz-Fejér means of double Walsh-Kaczmarz-Fourier series. (English) Zbl 1164.42321 Math. Pannonica 19, No. 1, 49-56 (2008). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Math. Pannonica 19, No. 1, 49--56 (2008; Zbl 1164.42321)
Goginava, Ushangi The weak type inequality for the Walsh system. (English) Zbl 1213.42098 Stud. Math. 185, No. 1, 35-48 (2008). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Stud. Math. 185, No. 1, 35--48 (2008; Zbl 1213.42098) Full Text: DOI
Goginava, Ushangi Convergence in measure of partial sums of double Fourier series with respect to the Walsh-Kaczmarz system. (English) Zbl 1204.42045 J. Math. Anal. Approx. Theory 2, No. 2, 160-167 (2007). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, J. Math. Anal. Approx. Theory 2, No. 2, 160--167 (2007; Zbl 1204.42045)
Goginava, U. Marcinkiewicz-Fejér means of double Vilenkin-Fourier series. (English) Zbl 1174.42034 Stud. Sci. Math. Hung. 44, No. 1, 97-115 (2007). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Stud. Sci. Math. Hung. 44, No. 1, 97--115 (2007; Zbl 1174.42034) Full Text: DOI
Goginava, Ushangi; Nagy, Károly On the Fejér means of double Fourier series with respect to the Walsh-Kaczmarz system. (English) Zbl 1174.42337 Period. Math. Hung. 55, No. 1, 11-18 (2007). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{K. Nagy}, Period. Math. Hung. 55, No. 1, 11--18 (2007; Zbl 1174.42337) Full Text: DOI
Goginava, Ushangi; Toledo, Rodolfo Convergence of walsh-Fourier series of a class \(BO(p(n)\uparrow \infty\)). (English) Zbl 1134.42331 Georgian Math. J. 14, No. 4, 643-650 (2007). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{R. Toledo}, Georgian Math. J. 14, No. 4, 643--650 (2007; Zbl 1134.42331)
Gát, György; Goginava, Ushangi Almost everywhere convergence of a subsequence of the logarithmic means of quadratic partial sums of double Walsh-Fourier series. (English) Zbl 1135.42327 Publ. Math. Debr. 71, No. 1-2, 173-184 (2007). MSC: 42C10 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, Publ. Math. Debr. 71, No. 1--2, 173--184 (2007; Zbl 1135.42327)
Goginava, Ushangi The maximal operator of the Fejér means of the character system of the p-series field in the Kaczmarz rearrangement. (English) Zbl 1136.42024 Publ. Math. Debr. 71, No. 1-2, 43-55 (2007). Reviewer: Manfred Tasche (Rostock) MSC: 42C10 40G05 PDFBibTeX XMLCite \textit{U. Goginava}, Publ. Math. Debr. 71, No. 1--2, 43--55 (2007; Zbl 1136.42024)
Goginava, U. Maximal operators of Fejér means of double Walsh-Fourier series. (English) Zbl 1174.42336 Acta Math. Hung. 115, No. 4, 333-340 (2007). MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Acta Math. Hung. 115, No. 4, 333--340 (2007; Zbl 1174.42336) Full Text: DOI
Blahota, István; Gát, György; Goginava, Ushangi Maximal operators of Fejér means of double Vilenkin-Fourier series. (English) Zbl 1117.42006 Colloq. Math. 107, No. 2, 287-296 (2007). MSC: 42C10 PDFBibTeX XMLCite \textit{I. Blahota} et al., Colloq. Math. 107, No. 2, 287--296 (2007; Zbl 1117.42006) Full Text: DOI
Goginava, Ushangi The maximal operator of Marcinkiewicz-Fejér means of the \(d\)-dimensional Walsh-Fourier series. (English) Zbl 1487.42067 East J. Approx. 12, No. 3, 295-302 (2006). MSC: 42C10 42B20 PDFBibTeX XMLCite \textit{U. Goginava}, East J. Approx. 12, No. 3, 295--302 (2006; Zbl 1487.42067)
Blahota, István; Gát, György; Goginava, Ushangi Maximal operators of Fejér means of Vilenkin-Fourier series. (English) Zbl 1232.42024 JIPAM, J. Inequal. Pure Appl. Math. 7, No. 4, Paper No. 149, 7 p. (2006). MSC: 42C10 PDFBibTeX XMLCite \textit{I. Blahota} et al., JIPAM, J. Inequal. Pure Appl. Math. 7, No. 4, Paper No. 149, 7 p. (2006; Zbl 1232.42024) Full Text: EuDML EMIS
Goginava, U. The maximal operator of the (C, \(\alpha\)) means of the Walsh-Fourier series. (English) Zbl 1121.42020 Ann. Univ. Sci. Budap. Rolando Eötvös, Sect. Comput. 26, 127-135 (2006). Reviewer: Alexei Lukashov (Istanbul) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Ann. Univ. Sci. Budap. Rolando Eötvös, Sect. Comput. 26, 127--135 (2006; Zbl 1121.42020)
Goginava, Ushangi On the approximation properties of partial sums of Walsh-Fourier series. (English) Zbl 1136.42023 Acta Sci. Math. 72, No. 3-4, 569-579 (2006). Reviewer: György Gát (Nyíregyháza) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, Acta Sci. Math. 72, No. 3--4, 569--579 (2006; Zbl 1136.42023)
Gát, Győrgy; Goginava, Ushangi Almost everywhere convergence of \((C,\alpha)\)-means of quadratical partial sums of double Vilenkin-Fourier series. (English) Zbl 1107.42006 Georgian Math. J. 13, No. 3, 447-462 (2006). MSC: 42C10 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, Georgian Math. J. 13, No. 3, 447--462 (2006; Zbl 1107.42006)
Goginava, U.; Tkebuchava, G. Convergence of subsequences of partial sums and logarithmic means of Walsh-Fourier series. (English) Zbl 1109.42008 Acta Sci. Math. 72, No. 1-2, 159-177 (2006). Reviewer: György Gát (Nyíregyháza) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava} and \textit{G. Tkebuchava}, Acta Sci. Math. 72, No. 1--2, 159--177 (2006; Zbl 1109.42008)
Gát, G.; Goginava, U.; Tkebuchava, G. Convergence in measure of logarithmic means of quadratical partial sums of double Walsh-Fourier series. (English) Zbl 1103.42016 J. Math. Anal. Appl. 323, No. 1, 535-549 (2006). MSC: 42C10 42B35 46E30 PDFBibTeX XMLCite \textit{G. Gát} et al., J. Math. Anal. Appl. 323, No. 1, 535--549 (2006; Zbl 1103.42016) Full Text: DOI
Gát, György; Goginava, Ushangi Maximal convergence space of a subsequence of the logarithmic means of rectangular partial sums of double Walsh-Fourier series. (English) Zbl 1103.42017 Real Anal. Exch. 31(2005-2006), No. 2, 447-464 (2006). MSC: 42C10 42B25 PDFBibTeX XMLCite \textit{G. Gát} and \textit{U. Goginava}, Real Anal. Exch. 31, No. 2, 447--464 (2006; Zbl 1103.42017) Full Text: DOI
Goginava, Ushangi Almost everywhere convergence of \((C,\alpha)\)-means of cubical partial sums of \(d\)-dimensional Walsh–Fourier series. (English) Zbl 1104.42015 J. Approximation Theory 141, No. 1, 8-28 (2006). Reviewer: Ferenc Weisz (Budapest) MSC: 42C10 PDFBibTeX XMLCite \textit{U. Goginava}, J. Approx. Theory 141, No. 1, 8--28 (2006; Zbl 1104.42015) Full Text: DOI
Gát, G.; Goginava, U.; Nagy, K. On \((H_{pq},L_{pq})\)-type inequality of maximal operator of Marcinkiewicz-Fejér means of double Fourier series with respect to the Kaczmarz system. (English) Zbl 1129.42355 Math. Inequal. Appl. 9, No. 3, 473-483 (2006). MSC: 42B20 42C10 PDFBibTeX XMLCite \textit{G. Gát} et al., Math. Inequal. Appl. 9, No. 3, 473--483 (2006; Zbl 1129.42355) Full Text: DOI