Boukoucha, Rachid. “EXPLICIT FORM FOR THE FIRST INTEGRAL AND LIMIT CYCLES OF A CLASS OF PLANAR KOLMOGOROV SYSTEMS”. Proceedings of the YSU A: Physical and Mathematical Sciences 55, no. 1 (254) (May 21, 2021): 1–11. Accessed May 17, 2024. https://journals.ysu.am/index.php/proceedings-phys-math/article/view/vol55_no1_2021_pp001-011.