RUKASOV, V. I.; SILIN, E. S. Approximation of Continuous Functions by de La Vallee-Poussin Operators. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 57, n. 2, p. 230–238, 2005. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3590. Acesso em: 6 dec. 2025.