ROMANYUK, V. S. Approximation of classes of analytic functions by algebraic polynomials and kolmogorov widths. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 48, n. 2, p. 236–250, 1996. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5351. Acesso em: 7 apr. 2025.