V. V. Myronyuk, “Kolmogorov widths of the anisotropic Besov classes of periodic functions of many variables”, Ukr. Mat. Zhurn., vol. 68, no. 5, pp. 634–643, May 2016, Accessed: Apr. 13, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/1867