Lyman, F. N. “On Groups With Minimality Condition for Noninvariant Abelian Pd-Subgroups”. Ukrains’kyi Matematychnyi Zhurnal, vol. 57, no. 2, Feb. 2005, pp. 265-70, https://umj.imath.kiev.ua/index.php/umj/article/view/3594.