SAVCHUK, V. V. Best linear methods for the approximation of functions of the Bergman class by algebraic polynomials. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 58, n. 12, p. 1674–1685, 2006. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3563. Acesso em: 6 dec. 2025.