SKASKIV, O. B. Rate of Convergence of Positive Series. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 56, n. 12, p. 1665–1674, 2004. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3873. Acesso em: 14 apr. 2025.