Muradov, F.Kh. “Ternary Semigroups of Topological Transformations”. Bulletin of the Karaganda University. Mathematics Series 102, no. 2 (June 30, 2021): 84–91. Accessed October 6, 2025. http://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/419.