MYRONYUK, V. V. Widths of the anisotropic Besov classes of periodic functions of several variables. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 68, n. 8, p. 1080–1091, 2016. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1903. Acesso em: 5 dec. 2025.