HEMBARS'KA, S. B.; ZADEREI, P. V. On the absolute convergence of power series. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 51, n. 5, p. 594–602, 1999. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4647. Acesso em: 6 dec. 2025.