Stepanets, O. I. (2002) “Approximation of Convolution Classes by Fourier Sums. New Results”, Ukrains’kyi Matematychnyi Zhurnal, 54(5), pp. 581-602. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4097 (Accessed: 25May2024).