Vardanyan, N.K. “ON CONSTANT COEFFICIENT PDE SYSTEMS AND INTERSECTION MULTIPLICITIES”. Proceedings of the YSU A: Physical and Mathematical Sciences 54, no. 2 (252) (August 17, 2020): 108–114. Accessed November 23, 2024. https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol54_no2_2020_pp108-114.