CHERNIKOV, S. N. Investigations of O. Yu Shmidt in the theory of infinite groups. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 23, n. 5, p. 591–597, 1971. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8331. Acesso em: 6 dec. 2025.