SERDYUK, A. S. Approximation of Poisson integrals by de la Valleé-Poussin sums in uniform and integral metrics. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 62, n. 12, p. 1672–1686, 2010. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2991. Acesso em: 14 apr. 2025.