Knyagina, V. N., and V. N. Tyutyanov. 2014. “Factorizations of Finite Groups into $r$-Soluble Subgroups With Given Embeddings”. Ukrains’kyi Matematychnyi Zhurnal 66 (10), 1431–1435. https://umj.imath.kiev.ua/index.php/umj/article/view/2235.