Piskun, M. M. and Semko, N. N. (2008) “On the application of some concepts of ring theory to the study of the influence of systems of subgroups of a group”, Ukrains’kyi Matematychnyi Zhurnal, 60(5), pp. 657–668. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/3184 (Accessed: 8May2024).