Petrus R, Younis A. The existence and convergence of the solution to a system of non-linear integral-differential equations of the first rank with the requirements of integration. EDUSJ [Internet]. 2006 Jan. 1 [cited 2025 Aug. 6];18(1):138-51. Available from: https://ojs.uomosul.edu.iq/index.php/edusj/article/view/23416