VOLCHKOV, V. V. On multiplicators of power series in Hardy spaces. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 50, n. 4, p. 585–587, 1998. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4927. Acesso em: 5 dec. 2025.