DeG. F., SysakY. P. and FranclosiS. (1997) “On ascending and subnormal subgroups of infinite factorized groups”, Ukrains’kyi Matematychnyi Zhurnal, 49(6), pp. 842–848. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/5070 (Accessed: 27July2024).