The Existence of a Polynomial Inverse Integrating Factors and Studies About the Limit Cycles for Cubic, Quartic and Quintic Polynomial Systems. Baghdad Sci.J [Internet]. 2021 Jun. 1 [cited 2024 May 3];18(2):0322. Available from: https://bsj.uobaghdad.edu.iq/index.php/BSJ/article/view/3623