Hazim Sadoon L, لمیاء. Use the perturbation method to find the solvability condition for a particular boundary value problem. EDUSJ [Internet]. 2009 Sep. 1 [cited 2025 Aug. 4];22(3):143-9. Available from: https://rjps.uomosul.edu.iq/index.php/edusj/article/view/18184