First Integrals and a Zero-Hopf Bifurcation of the Four-Dimensional Lotka-Volterra Systems. Iraqi Journal of Science [Internet]. 2024 Sep. 30 [cited 2024 Dec. 30];65(9):5171-8. Available from: https://ijs.uobaghdad.edu.iq/index.php/eijs/article/view/10325