KOLYADA, V. I. On Cèsaro and Copson norms of nonnegative sequences. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 71, n. 2, p. 220–229, 2019. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1433. Acesso em: 5 dec. 2025.