SAVCHUK, V. V.; SAVCHUK, M. V. Approximation of holomorphic functions of Zygmund class by Fejer means. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 64, n. 8, p. 1148–1152, 2012. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2648. Acesso em: 5 dec. 2025.