VakarchukS. B. (2016) “Jackson-type inequalities with generalized modulus of continuity and exact values of the $n$-widths of the classes of $(ψ,β)$-differential functions in $L_2$. I”, Ukrains’kyi Matematychnyi Zhurnal, 68(6), pp. 723-745. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/1874 (Accessed: 21November2024).