Hambardzumyan, S. R. “ON THE STABILITY BY ACTING FORCE WITH PAIR IMAGINING ROOTS FOR THE SECOND ORDER SYSTEM”. Proceedings of the YSU A: Physical and Mathematical Sciences 37, no. 3 (202) (October 9, 2003): 50–56. Accessed January 22, 2026. https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol37_no3_2003_pp050-056.