Parfinovych, N. V. (2017) “Exact values of the best (α, β) -approximations of classes of convolutions with kernels that do not increase the number of sign changes”, Ukrains’kyi Matematychnyi Zhurnal, 69(8), pp. 1073-1083. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/1759 (Accessed: 29March2024).