Musin, A.T. “Canonisation Reper of Complex of Lines of Theree-Dimensional Flag”. Bulletin of the Karaganda University. Mathematics Series 84, no. 4 (December 30, 2016): 104–109. Accessed August 23, 2025. http://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/132.