Zenkov, A.V. “On Varieties of m–groups With Identety X_*^n=X^-N”. Bulletin of the Karaganda University. Mathematics Series 80, no. 4 (December 29, 2015): 82–85. Accessed July 10, 2025. https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/64.