LiY., and QiaoS. “On Weakly <i>s</I&gt; -Normal Subgroups of Finite Groups”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 63, no. 11, Nov. 2011, pp. 1555-64, https://umj.imath.kiev.ua/index.php/umj/article/view/2825.