Approximation of periodic functions of two variables by Vallée-Poussin sums
English version (Springer): Ukrainian Mathematical Journal 30 (1978), no. 1, pp 23-31.
Citation Example: Stepanets O. I., Zaderei P. V. Approximation of periodic functions of two variables by Vallée-Poussin sums // Ukr. Mat. Zh. - 1978. - 30, № 1. - pp. 33–44.
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