CHERNIKOV, S. N. Infinite non-Abelian groups where all the infinite non-Abelian subgroups are invariant. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 23, n. 5, p. 604–628, 1971. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8333. Acesso em: 6 dec. 2025.