Bilotskii, N. N., & Baryshovets, P. P. (2010). On groups with a small number of classes of conjugate noncomplemented subgroups. Ukrains’kyi Matematychnyi Zhurnal, 62(10), 1420–1427. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/2966