Kurdachenko, L.A., I.Ya. Subbotin, and T.V. Velychko. “On the Nonperiodic Groups, Whose Subgroups of Infinite Special Rank Are Transitively Normal”. Reports of the National Academy of Sciences of Ukraine, no. 2 (March 28, 2024): 3–6. Accessed July 22, 2025. https://nasu-periodicals.org.ua/index.php/dp/article/view/2020-2-1.