Trofimuk, A. A., and D. V. Gritsuk. “The Derived $p$-Length of a $p$-Solvable Group With Bounded Indices of Fitting $p$-Subgroups in Its Normal Closures”. Ukrains’kyi Matematychnyi Zhurnal 72, no. 3 (March 28, 2020): 366-370. Accessed March 29, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/629.