KOVALEVA, V. A. Finite groups with given systems of $K-\mathfrak{U}$-subnormal subgroups. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 68, n. 1, p. 52–63, 2016. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1821. Acesso em: 5 dec. 2025.