Mustafa, Sirwan A., and Niazy H. Hussen. “First Integrals and a Zero-Hopf Bifurcation of the Four-Dimensional Lotka-Volterra Systems”. Iraqi Journal of Science 65, no. 9 (September 30, 2024): 5171–5181. Accessed December 7, 2025. https://www.ijs.uobaghdad.edu.iq/index.php/eijs/article/view/10325.