PYPKA, A. A. On the relationships between the central series in some locally finite groups. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 68, n. 10, p. 1437–1441, 2016. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1931. Acesso em: 7 apr. 2025.