S. A. . Mustafa and N. H. . Hussen, “First Integrals and a Zero-Hopf Bifurcation of the Four-Dimensional Lotka-Volterra Systems”, Iraqi Journal of Science, vol. 65, no. 9, pp. 5171–5181, Sep. 2024, doi: 10.24996/ijs.2024.65.9.31.