ROMANYUK, A. S. The best trigonometric approximations and the Kolmogorov diameters of the Besov classes of functions of many variables. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 45, n. 5, p. 663–675, 1993. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5853. Acesso em: 14 apr. 2025.