PLICHKO , A. M. Automatic continuity, bases and radicals in the metrized algebras . Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 44, n. 8, p. 1129–1132, 1992. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8046. Acesso em: 5 dec. 2025.