Berisha, N. Sh.; Berisha, F. M. Approximating classes of functions defined by operators of differentiation or operators of generalised translation by means of algebraic polynomials. (English) Zbl 1254.41016 Int. J. Math. Anal., Ruse 6, No. 53-56, 2709-2727 (2012). MSC: 41A35 41A50 42A16 PDF BibTeX XML Cite \textit{N. Sh. Berisha} and \textit{F. M. Berisha}, Int. J. Math. Anal., Ruse 6, No. 53--56, 2709--2727 (2012; Zbl 1254.41016) Full Text: arXiv Link
Berisha, M. Q.; Berisha, F. M. A note on the inverse theorem for a generalised modulus of smoothness. (English) Zbl 1274.42001 Mat. Bilt. 25, 91-96 (2001). MSC: 42A05 42A10 PDF BibTeX XML Cite \textit{M. Q. Berisha} and \textit{F. M. Berisha}, Mat. Bilt. 25, 91--96 (2001; Zbl 1274.42001) Full Text: arXiv