[1] Pustovoitov N N. Representation and approximation of multivariate periodic functions with a given mod-
ulus of smoothness. Analysis Math, 1994, 20: 35-48
[2] Sun Yongsheng, Wang Heping. Representation and approximation of multivariate functions with bounded
mixed moduli of smoothness. Proceedings of the Steklov Institute of Mathematics, 1997, 219: 350-371
[3] Pinkus A. N-widths in Approximation Theory. New York: Springer-Verlag, 1985
[4] Romaniuk A S. Optimal trigonometric approximation and Kolmogorov widths for Besov classes of multi-
variate functions. Ukr Mat Zh, 1993, 45(5): 663-675
[5] Romaniuk A S. Kolmogorov widths for classes Br
p, of multivariate periodic functions with small smooth-
ness in the space Lq. Ukr Mat Zh, 1994, 46(7): 915-926
[6] Nikol’skii S M. Approximation of Functions of Several Variables and Imbedding Theorems. New York:
Spring-Verlag, 1975
[7] Liu Yongping, Xu Guiqiao. The Infinite-dimensional widths and optimal recovery of gengralized Besov
Classes. Journal of Complexity, 2002, 18: 815-832
[8] Zygmund A. Trigonometric Series II. New York: Cambridge Univ Press, 1959
[9] Temlyakov V N. Approximation of Periodic Functions. New York: Nova Science Publishers, Inc, 1993
[10] Xu Guiqiao, Yu Chunwu. The Gel’fand n-widths of multivariate periodic Besov classes. Acta Mathematica
Scientia, 2003, 23B(3): 399-404
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