PiskunM. M. and SemkoN. N. (2009) “On some generalizations of nearly normal subgroups”, Ukrains’kyi Matematychnyi Zhurnal, 61(10), pp. 1381-1395. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/3108 (Accessed: 24November2024).