Azletskу S. P. On a theorem on characteristic subgroups of a finite group. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 18, n. 1, p. 102–104, 1966. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8657. Acesso em: 6 dec. 2025.