Faeq, Isam R., and Shwan O. Abdalrahman. “ The Stability and Catastrophic Behavior of Finite Periodic Solutions in Non-Linear Differential Equations ”. Tikrit Journal of Pure Science 28, no. 6 (December 25, 2023): 146–152. Accessed October 22, 2026. http://www.tjpsj.org/index.php/tjps/article/view/1382.