X. H. Li and Y. Xu, “$s$-Conditionally Permutable Subgroups and $p$-Nilpotency of Finite Groups”, Ukr. Mat. Zhurn., vol. 66, no. 6, pp. 858–864, Jun. 2014, Accessed: Apr. 22, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/2184