CharinV. S. “On the Theory of Groups With Generalized Minimality Condition for Closed Subgroups”. Ukrains’kyi Matematychnyi Zhurnal 51, no. 3 (March 25, 1999): 398–409. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4623.