Khachatryan, N.A. “INTERVAL NON-TOTAL COLORABLE GRAPHS”. Proceedings of the YSU A: Physical and Mathematical Sciences 49, no. 3 (238) (December 15, 2015): 37–41. Accessed May 19, 2024. https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol49_no3_2015_pp037-041.