ZHMUD, É. M. On the multiplier of a group with nontrivial center. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 47, n. 4, p. 546–550, 1995. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5455. Acesso em: 5 dec. 2025.