StasyukS. A. and FedunykO. V. (2006) “Approximation characteristics of the classes $B_{p,θ}^{Ω}$ of periodic functions of many variables”, Ukrains’kyi Matematychnyi Zhurnal, 58(5), pp. 692–704. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/3486 (Accessed: 22November2024).