Li, C., X. Yi, and Xirong Zhang. “A Note on $SΦ$-Supplemented Subgroups”. Ukrains’kyi Matematychnyi Zhurnal 68, no. 8 (August 25, 2016): 1139-1141. Accessed March 28, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/1908.