Geller, William; Misiurewicz, Michał Travel in an infinite desert. (English) Zbl 1502.05015 Am. Math. Mon. 129, No. 10, 913-923 (2022). MSC: 05A16 37B40 37C35 PDFBibTeX XMLCite \textit{W. Geller} and \textit{M. Misiurewicz}, Am. Math. Mon. 129, No. 10, 913--923 (2022; Zbl 1502.05015) Full Text: DOI
Geller, William; Misiurewicz, Michał Coarse entropy. (English) Zbl 1482.37020 Fundam. Math. 255, No. 1, 91-109 (2021). Reviewer: Takuma Imamura (Tokyo) MSC: 37B40 28D20 51F30 PDFBibTeX XMLCite \textit{W. Geller} and \textit{M. Misiurewicz}, Fundam. Math. 255, No. 1, 91--109 (2021; Zbl 1482.37020) Full Text: DOI arXiv
Misiurewicz, Michał; Zhang, Hong-Kun Topological entropy of Bunimovich stadium billiards. (English) Zbl 1476.37049 Pure Appl. Funct. Anal. 6, No. 1, 221-229 (2021). Reviewer: Hasan Akin (Trieste) MSC: 37C83 37B40 37B10 PDFBibTeX XMLCite \textit{M. Misiurewicz} and \textit{H.-K. Zhang}, Pure Appl. Funct. Anal. 6, No. 1, 221--229 (2021; Zbl 1476.37049) Full Text: arXiv Link
Geller, William; Misiurewicz, Michał; Sawicki, Damian Coarse entropy of metric spaces. arXiv:2109.15172 Preprint, arXiv:2109.15172 [math.MG] (2021). MSC: 51F30 37B40 BibTeX Cite \textit{W. Geller} et al., ``Coarse entropy of metric spaces'', Preprint, arXiv:2109.15172 [math.MG] (2021) Full Text: arXiv OA License
Bielawski, Jakub; Chotibut, Thiparat; Falniowski, Fryderyk; Kosiorowski, Grzegorz; Misiurewicz, Michał; Piliouras, Georgios Follow-the-Regularized-Leader Routes to Chaos in Routing Games. arXiv:2102.07974 Preprint, arXiv:2102.07974 [cs.GT] (2021). MSC: 74H65 91A13 68W27 37B40 BibTeX Cite \textit{J. Bielawski} et al., ``Follow-the-Regularized-Leader Routes to Chaos in Routing Games'', Preprint, arXiv:2102.07974 [cs.GT] (2021) Full Text: arXiv OA License
Alsedà, Lluís; Misiurewicz, Michał; Pérez, Rodrigo A. Flexibility of entropies for piecewise expanding unimodal maps. arXiv:2004.01813 Preprint, arXiv:2004.01813 [math.DS] (2020). MSC: 37A35 37B40 37E05 BibTeX Cite \textit{L. Alsedà} et al., ``Flexibility of entropies for piecewise expanding unimodal maps'', Preprint, arXiv:2004.01813 [math.DS] (2020) Full Text: arXiv OA License
Cosper, David; Misiurewicz, Michał Entropy locking. (English) Zbl 1394.37069 Fundam. Math. 241, No. 1, 83-96 (2018). MSC: 37E05 37B40 PDFBibTeX XMLCite \textit{D. Cosper} and \textit{M. Misiurewicz}, Fundam. Math. 241, No. 1, 83--96 (2018; Zbl 1394.37069) Full Text: DOI Link
Misiurewicz, Michał; Rodrigues, Ana Counting preimages. (English) Zbl 1457.37021 Ergodic Theory Dyn. Syst. 38, No. 5, 1837-1856 (2018). MSC: 37B40 37E05 37B51 37C15 PDFBibTeX XMLCite \textit{M. Misiurewicz} and \textit{A. Rodrigues}, Ergodic Theory Dyn. Syst. 38, No. 5, 1837--1856 (2016; Zbl 1457.37021) Full Text: DOI Link
Alsedà, Lluís; Misiurewicz, Michał Semiconjugacy to a map of a constant slope. (English) Zbl 1343.37020 Discrete Contin. Dyn. Syst., Ser. B 20, No. 10, 3403-3413 (2015). MSC: 37E05 37B40 PDFBibTeX XMLCite \textit{L. Alsedà} and \textit{M. Misiurewicz}, Discrete Contin. Dyn. Syst., Ser. B 20, No. 10, 3403--3413 (2015; Zbl 1343.37020) Full Text: DOI arXiv
Misiurewicz, Michał Spectral radius of a nonnegative matrix: from rome to indy. (English) Zbl 1291.37023 Proc. Am. Math. Soc. 141, No. 11, 3977-3983 (2013). Reviewer: Geoffrey R. Goodson (Towson) MSC: 37B40 15A18 05C50 05C20 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Proc. Am. Math. Soc. 141, No. 11, 3977--3983 (2013; Zbl 1291.37023) Full Text: DOI
Geller, William; Kitchens, Bruce; Misiurewicz, Michał; Rams, Michał A spectral radius estimate and entropy of hypercubes. (English) Zbl 1258.37016 Int. J. Bifurcation Chaos Appl. Sci. Eng. 22, No. 4, Paper No. 1250096, 6 p. (2012). MSC: 37B40 37N25 PDFBibTeX XMLCite \textit{W. Geller} et al., Int. J. Bifurcation Chaos Appl. Sci. Eng. 22, No. 4, Paper No. 1250096, 6 p. (2012; Zbl 1258.37016) Full Text: DOI
Llibre, Jaume; Misiurewicz, Michał Negative periodic orbits for graph maps. (English) Zbl 1087.37034 Nonlinearity 19, No. 3, 741-746 (2006). MSC: 37E25 37B40 PDFBibTeX XMLCite \textit{J. Llibre} and \textit{M. Misiurewicz}, Nonlinearity 19, No. 3, 741--746 (2006; Zbl 1087.37034) Full Text: DOI
Kwietniak, Dominik; Misiurewicz, Michał Exact Devaney chaos and entropy. (English) Zbl 1119.37027 Qual. Theory Dyn. Syst. 6, No. 1, 169-179 (2005). MSC: 37D45 37B40 37E10 PDFBibTeX XMLCite \textit{D. Kwietniak} and \textit{M. Misiurewicz}, Qual. Theory Dyn. Syst. 6, No. 1, 169--179 (2005; Zbl 1119.37027) Full Text: DOI
Misiurewicz, Michał; Raith, Peter Strict inequalities for the entropy of transitive piecewise monotone maps. (English) Zbl 1078.37032 Discrete Contin. Dyn. Syst. 13, No. 2, 451-468 (2005). MSC: 37E05 37B40 PDFBibTeX XMLCite \textit{M. Misiurewicz} and \textit{P. Raith}, Discrete Contin. Dyn. Syst. 13, No. 2, 451--468 (2005; Zbl 1078.37032) Full Text: DOI
Misiurewicz, Michał Entropy of maps with horizontal gaps. (English) Zbl 1099.37012 Int. J. Bifurcation Chaos Appl. Sci. Eng. 14, No. 4, 1489-1492 (2004). MSC: 37B40 37E05 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Int. J. Bifurcation Chaos Appl. Sci. Eng. 14, No. 4, 1489--1492 (2004; Zbl 1099.37012) Full Text: DOI
Misiurewicz, Michał On Bowen’s definition of topological entropy. (English) Zbl 1056.37016 Discrete Contin. Dyn. Syst. 10, No. 3, 827-833 (2004). Reviewer: Victor I. Tkachenko (Kyïv) MSC: 37B40 37C45 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Discrete Contin. Dyn. Syst. 10, No. 3, 827--833 (2004; Zbl 1056.37016) Full Text: DOI
Misiurewicz, Michał Permutations and topological entropy for interval maps. (English) Zbl 1030.37025 Nonlinearity 16, No. 3, 971-976 (2003). MSC: 37E05 37B40 37E15 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Nonlinearity 16, No. 3, 971--976 (2003; Zbl 1030.37025) Full Text: DOI
Misiurewicz, Michał Possible jumps of entropy for interval maps. (English) Zbl 1064.37030 Qual. Theory Dyn. Syst. 2, No. 2, 289-306 (2002). MSC: 37E05 37B40 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Qual. Theory Dyn. Syst. 2, No. 2, 289--306 (2002; Zbl 1064.37030) Full Text: DOI
Franks, John; Misiurewicz, Michał Topological methods in dynamics. (English) Zbl 1048.37001 Hasselblatt, B. (ed.) et al., Handbook of dynamical systems. Volume 1A. Amsterdam: North-Holland (ISBN 0-444-82669-6/hbk). 547-598 (2002). Reviewer: Roman Srzednicki (Kraków) MSC: 37-02 37B30 37C30 37D05 37E15 37B35 37B40 37E30 PDFBibTeX XMLCite \textit{J. Franks} and \textit{M. Misiurewicz}, in: Handbook of dynamical systems. Volume 1A. Amsterdam: North-Holland. 547--598 (2002; Zbl 1048.37001)
Misiurewicz, Michał; Zgliczyński, Piotr Topological entropy for multidimensional perturbations of one-dimensional maps. (English) Zbl 1090.37507 Int. J. Bifurcation Chaos Appl. Sci. Eng. 11, No. 5, 1443-1446 (2001). MSC: 37B40 37E05 PDFBibTeX XMLCite \textit{M. Misiurewicz} and \textit{P. Zgliczyński}, Int. J. Bifurcation Chaos Appl. Sci. Eng. 11, No. 5, 1443--1446 (2001; Zbl 1090.37507) Full Text: DOI
Alsedà, Lluís; Llibre, Jaume; Misiurewicz, Michał Combinatorial dynamics and entropy in dimension one. 2nd ed. (English) Zbl 0963.37001 Advanced Series in Nonlinear Dynamics. 5. Singapore: World Scientific. xvi, 415 p. (2000). Reviewer: Alois Klíč (Praha) MSC: 37-02 37E05 37E10 37E15 37E25 37E45 37A05 37B40 PDFBibTeX XMLCite \textit{L. Alsedà} et al., Combinatorial dynamics and entropy in dimension one. 2nd ed. Singapore: World Scientific (2000; Zbl 0963.37001)
Kolyada, Sergii; Misiurewicz, Michał; Snoha, Ľubomír Topological entropy of nonautonomous piecewise monotone dynamical systems on the interval. (English) Zbl 0936.37004 Fundam. Math. 160, No. 2, 161-181 (1999). Reviewer: Alexei Ivanov (St.Peterburg) MSC: 37B40 54H20 37B55 54C70 PDFBibTeX XMLCite \textit{S. Kolyada} et al., Fundam. Math. 160, No. 2, 161--181 (1999; Zbl 0936.37004) Full Text: EuDML
Geller, William; Misiurewicz, Michał Rotation and entropy. (English) Zbl 0918.54019 Trans. Am. Math. Soc. 351, No. 7, 2927-2948 (1999). Reviewer: Mike Hurley (Cleveland) MSC: 54C70 37A99 54H20 28D20 PDFBibTeX XMLCite \textit{W. Geller} and \textit{M. Misiurewicz}, Trans. Am. Math. Soc. 351, No. 7, 2927--2948 (1999; Zbl 0918.54019) Full Text: DOI
Alsedà, Lluís; Baldwin, Stewart; Llibre, Jaume; Misiurewicz, Michał Entropy of transitive tree maps. (English) Zbl 0887.58013 Topology 36, No. 2, 519-532 (1997). Reviewer: M.Denker (Göttingen) MSC: 37E99 54C70 54H20 28D20 PDFBibTeX XMLCite \textit{L. Alsedà} et al., Topology 36, No. 2, 519--532 (1997; Zbl 0887.58013) Full Text: DOI
Blokh, A.; Misiurewicz, M. Entropy and over-rotation numbers for interval maps. (English) Zbl 0911.58014 Proc. Steklov Inst. Math. 216, 229-235 (1997) and Tr. Mat. Inst. Steklova 216, 236-242 (1997). Reviewer: Nikolai Chernov (Birmingham (Alabama)) MSC: 37E99 37C25 54C70 PDFBibTeX XMLCite \textit{A. Blokh} and \textit{M. Misiurewicz}, in: Dinamicheskie sistemy i smezhnye voprosy. Sbornik statej. K 60-letiyu so dnya rozhdeniya akademika D. V. Anosova. Moskva: Nauka. MAIK Nauka. 236--242 (1997; Zbl 0911.58014)
Blokh, Alexander; Misiurewicz, Michał Entropy of twist interval maps. (English) Zbl 0885.54016 Isr. J. Math. 102, 61-99 (1997). Reviewer: Michael L.Blank (Moskva) MSC: 54C70 28D20 37C25 PDFBibTeX XMLCite \textit{A. Blokh} and \textit{M. Misiurewicz}, Isr. J. Math. 102, 61--99 (1997; Zbl 0885.54016) Full Text: DOI
Misiurewicz, Michał Continuity of entropy revisited. (English) Zbl 0901.28014 Agarwal, R. P. (ed.), Dynamical systems and applications. Singapore: World Scientific. World Sci. Ser. Appl. Anal. 4, 495-503 (1995). Reviewer: M.Denker (Göttingen) MSC: 28D20 37A99 54H20 54C70 PDFBibTeX XMLCite \textit{M. Misiurewicz}, World Sci. Ser. Appl. Anal. 4, 495--503 (1995; Zbl 0901.28014)
Misiurewicz, Michał Minor cycles for interval maps. (English) Zbl 0818.58014 Fundam. Math. 145, No. 3, 281-304 (1994). Reviewer: A.Klíč (Praha) MSC: 37E99 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Fundam. Math. 145, No. 3, 281--304 (1994; Zbl 0818.58014) Full Text: DOI EuDML
Alsedà, Lluis; Llibre, Jaume; Misiurewicz, Michał Combinatorial dynamics and entropy in dimension one. (English) Zbl 0843.58034 Advanced Series in Nonlinear Dynamics. 5. Singapore: World Scientific. xi, 329 p. (1993). Reviewer: A.Quas (Cambridge) MSC: 37E99 37-02 37A99 28D20 54C70 PDFBibTeX XMLCite \textit{L. Alsedà} et al., Combinatorial dynamics and entropy in dimension one. Singapore: World Scientific (1993; Zbl 0843.58034)
Llibre, Jaume; Misiurewicz, Michał Horseshoes, entropy and periods for graph maps. (English) Zbl 0787.54021 Topology 32, No. 3, 649-664 (1993). Reviewer: E.Outerelo (Madrid) MSC: 54C70 54H20 PDFBibTeX XMLCite \textit{J. Llibre} and \textit{M. Misiurewicz}, Topology 32, No. 3, 649--664 (1993; Zbl 0787.54021) Full Text: DOI
Misiurewicz, M.; Tolosa, J. Entropy of snakes and the restricted variational principle. (English) Zbl 0784.54025 Ergodic Theory Dyn. Syst. 12, No. 4, 791-802 (1992). Reviewer: E.Petrisor (Timişoara) MSC: 54C70 37A99 PDFBibTeX XMLCite \textit{M. Misiurewicz} and \textit{J. Tolosa}, Ergodic Theory Dyn. Syst. 12, No. 4, 791--802 (1992; Zbl 0784.54025) Full Text: DOI
Brucks, K. M.; Misiurewicz, M.; Tresser, C. Monotonicity properties of the family of trapezoidal maps. (English) Zbl 0721.58017 Commun. Math. Phys. 137, No. 1, 1-12 (1991). Reviewer: G.Swiatek (Stony Brook) MSC: 37E99 54C70 37C85 PDFBibTeX XMLCite \textit{K. M. Brucks} et al., Commun. Math. Phys. 137, No. 1, 1--12 (1991; Zbl 0721.58017) Full Text: DOI
Misiurewicz, M.; Visinescu, E. Kneading sequences of skew tent maps. (English) Zbl 0715.58029 Ann. Inst. Henri Poincaré, Probab. Stat. 27, No. 1, 125-140 (1991). MSC: 37D99 54C70 PDFBibTeX XMLCite \textit{M. Misiurewicz} and \textit{E. Visinescu}, Ann. Inst. Henri Poincaré, Probab. Stat. 27, No. 1, 125--140 (1991; Zbl 0715.58029) Full Text: Numdam EuDML
Misiurewicz, Michał; Nitecki, Zbigniew Combinatorial patterns for maps of the interval. (English) Zbl 0745.58019 Mem. Am. Math. Soc. 456, 112 p. (1991). Reviewer: S.Yu.Pilyugin (St.Petersburg) MSC: 37B40 37C25 54H20 26A18 PDFBibTeX XMLCite \textit{M. Misiurewicz} and \textit{Z. Nitecki}, Combinatorial patterns for maps of the interval. Providence, RI: American Mathematical Society (AMS) (1991; Zbl 0745.58019) Full Text: DOI
Misiurewicz, Michał; Shlyachkov, Sergej V. Entropy of piecewise continuous interval maps. (English) Zbl 1026.37504 Mira, Ch. (ed.) et al., Iteration theory. Proceedings of the 7th European conference, ECIT ’89, Batschuns, Austria, September 10-16, 1989. Singapore: World Scientific. 239-245 (1991). MSC: 37B40 37E05 37D45 26A18 PDFBibTeX XMLCite \textit{M. Misiurewicz} and \textit{S. V. Shlyachkov}, in: Iteration theory. Proceedings of the 7th European conference, ECIT '89, Batschuns, Austria, September 10--16, 1989. Singapore: World Scientific. 239--245 (1991; Zbl 1026.37504)
Misiurewicz, Michał Jumps of entropy in one dimension. (English) Zbl 0694.54019 Fundam. Math. 132, No. 3, 215-226 (1989). Reviewer: M.Sears MSC: 54C70 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Fundam. Math. 132, No. 3, 215--226 (1989; Zbl 0694.54019) Full Text: DOI EuDML
Alsedà, L.; Llibre, J.; Misiurewicz, M.; Tresser, Charles Periods and entropy for Lorenz-like maps. (English) Zbl 0678.34047 Ann. Inst. Fourier 39, No. 4, 929-952 (1989). Reviewer: L.Alseta MSC: 37-XX 54H20 PDFBibTeX XMLCite \textit{L. Alsedà} et al., Ann. Inst. Fourier 39, No. 4, 929--952 (1989; Zbl 0678.34047) Full Text: DOI Numdam EuDML
Misiurewicz, M.; Smítal, J. Smooth chaotic maps with zero topological entropy. (English) Zbl 0689.58028 Ergodic Theory Dyn. Syst. 8, No. 3, 421-424 (1988). Reviewer: A.Boyarsky MSC: 37D45 37A99 PDFBibTeX XMLCite \textit{M. Misiurewicz} and \textit{J. Smítal}, Ergodic Theory Dyn. Syst. 8, No. 3, 421--424 (1988; Zbl 0689.58028) Full Text: DOI
Alsedà, Lluís; Llibre, Jaume; Mañosas, Francesc; Misiurewicz, Michał Lower bounds of the topological entropy for continuous maps of the circle of degree one. (English) Zbl 0663.54023 Nonlinearity 1, No. 3, 463-479 (1988). Reviewer: S.Kono MSC: 54H20 54C70 PDFBibTeX XMLCite \textit{L. Alsedà} et al., Nonlinearity 1, No. 3, 463--479 (1988; Zbl 0663.54023) Full Text: DOI
Misiurewicz, Michał; Ziemian, Krystyna Rate of convergence for computing entropy of some one-dimensional maps. (English) Zbl 0641.58026 Ergodic theory and related topics II, Proc. Conf., Georgenthal/GDR 1986, Teubner-Texte Math. 94, 147-159 (1987). Reviewer: H.Crauel MSC: 37A99 28D20 PDFBibTeX XML
Ledrappier, F.; Misiurewicz, M. Dimension of invariant measures for maps with exponent zero. (English) Zbl 0608.28008 Ergodic Theory Dyn. Syst. 5, 595-610 (1985). Reviewer: K.Krzyżewski MSC: 28D20 37A99 PDFBibTeX XMLCite \textit{F. Ledrappier} and \textit{M. Misiurewicz}, Ergodic Theory Dyn. Syst. 5, 595--610 (1985; Zbl 0608.28008) Full Text: DOI
Alsedà, Lluís; Llibre, Jaume; Misiurewicz, Michał; Simó, Carles Twist periodic orbits and topological entropy for continuous maps of the circle of degree one which have a fixed point. (English) Zbl 0592.54037 Ergodic Theory Dyn. Syst. 5, 501-517 (1985). Reviewer: J.Matkowski MSC: 54H20 54C70 PDFBibTeX XMLCite \textit{L. Alsedà} et al., Ergodic Theory Dyn. Syst. 5, 501--517 (1985; Zbl 0592.54037) Full Text: DOI
Misiurewicz, Michał Maps of an interval. (English) Zbl 0565.58025 Chaotic behaviour of deterministic systems, Les Houches/Fr. 1981, Sess. 36, 565-590 (1983). Reviewer: M.Min-Oo MSC: 37D45 37C70 37A99 PDFBibTeX XML
Misiurewicz, Michal Attracting Cantor set of positive measure for a \(C^\infty\) map of an interval. (English) Zbl 0522.58032 Ergodic Theory Dyn. Syst. 2, 405-415 (1982). MSC: 37C70 37G99 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Ergodic Theory Dyn. Syst. 2, 405--415 (1982; Zbl 0522.58032)
Misiurewicz, Michal Structure of mappings of an interval with zero entropy. (English) Zbl 0477.58030 Publ. Math., Inst. Hautes Étud. Sci. 53, 5-17 (1981). MSC: 37D45 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Publ. Math., Inst. Hautes Étud. Sci. 53, 5--17 (1981; Zbl 0477.58030) Full Text: DOI Numdam EuDML
Misiurewicz, Michal Absolutely continuous measures for certain maps of an interval. (English) Zbl 0477.58020 Publ. Math., Inst. Hautes Étud. Sci. 53, 17-51 (1981). MSC: 37A99 37D45 28D20 54C70 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Publ. Math., Inst. Hautes Étud. Sci. 53, 17--51 (1981; Zbl 0477.58020) Full Text: DOI Numdam EuDML
Misiurewicz, Michal Topological entropy and metric entropy. (English) Zbl 0473.54031 Theorie ergodique, Semin. Les Plans-sur-Bex 1980, Monogr. L’Enseign. Math. 29, 61-66 (1981). MSC: 54H20 54C70 28D05 PDFBibTeX XML
Block, Louis; Guckenheimer, John; Misiurewicz, Michal; Young, Lai Sang Periodic points and topological entropy of one dimensional maps. (English) Zbl 0447.58028 Global theory of dynamical systems, Proc. int. Conf., Evanston/Ill. 1979, Lect. Notes Math. 819, 18-34 (1980). MSC: 37C25 37A99 28D20 54C70 54H20 PDFBibTeX XML
Misiurewicz, M.; Szlenk, W. Entropy of piecewise monotone mappings. (English) Zbl 0445.54007 Stud. Math. 67, 45-63 (1980). MSC: 54C70 PDFBibTeX XMLCite \textit{M. Misiurewicz} and \textit{W. Szlenk}, Stud. Math. 67, 45--63 (1980; Zbl 0445.54007) Full Text: DOI EuDML
Misiurewicz, Michal Horseshoes for mappings of the interval. (English) Zbl 0459.54031 Bull. Acad. Pol. Sci., Sér. Sci. Math. 27, 167-169 (1979). MSC: 54A20 54C70 37C25 54H20 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Bull. Acad. Pol. Sci., Sér. Sci. Math. 27, 167--169 (1979; Zbl 0459.54031)
Misiurewicz, Michal Invariant measures for continuous transformations of (0,1) with zero topological entropy. (English) Zbl 0415.28015 Ergodic theory, Proc., Oberwolfach 1978, Lect. Notes Math. 729, 144-152 (1979). MSC: 28D05 54H20 PDFBibTeX XML
Misiurewicz, M. On non-continuity of topological entropy. (English) Zbl 0208.52101 Bull. Acad. Pol. Sci., Sér. Sci. Math. Astron. Phys. 19, 319-320 (1971). MSC: 54C70 57R50 58C07 PDFBibTeX XMLCite \textit{M. Misiurewicz}, Bull. Acad. Pol. Sci., Sér. Sci. Math. Astron. Phys. 19, 319--320 (1971; Zbl 0208.52101)