Xiaolan, Yi, and O. L. Shemetkova. “Finite Groups With System of <em class="a-Plus-plus">SE</Em&gt;-Supplemented Subgroups”. Ukrains’kyi Matematychnyi Zhurnal 65, no. 9 (September 25, 2013): 1227–1235. Accessed March 29, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2503.