Department of Mathematics and Mechanics, Editorial board “Proceedings of the YSU”, YSU administration,. “VLADIMIR S. SARGSYAN”. Proceedings of the YSU A: Physical and Mathematical Sciences 47, no. 1 (230) (April 10, 2013): 65–66. Accessed November 23, 2024. https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol47_no1_2013_pp065-066.