MYRONYUK, V. V. Trigonometric Approximations and Kolmogorov Widths of Anisotropic Besov Classes of Periodic Functions of Several Variables. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 66, n. 8, p. 1117–1132, 2014. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2203. Acesso em: 7 apr. 2025.