RUMP, W. I-radicals and right perfect rings. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 59, n. 7, p. 1005–1008, 2007. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3363. Acesso em: 14 apr. 2025.