J. Al-Sawoor, A., آن, A. Samarchi, M., & میرنا. (2025). An Application of He’s Variational Iteration Method for Solving Duffing - Van Der Pol Equation. AL-Rafidain Journal of Computer Sciences and Mathematics, 10(2), 153–163. Retrieved from https://rjps.uomosul.edu.iq/index.php/csmj/article/view/19431