SYSAK , Ya. P. Finite $ABA$-groups with Abelian $p$-subgroups $A$ and $B$. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 40, n. 3, p. 356–361, 1988. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/9149. Acesso em: 7 dec. 2025.