HAZIM SADOON, L.; لمیاء. Use the perturbation method to find the solvability condition for a particular boundary value problem. Journal of Education and Science (JES), [S. l.], v. 22, n. 3, p. 143–149, 2009. DOI: 10.33899/edusj.2009.57776. Disponível em: https://rjps.uomosul.edu.iq/index.php/edusj/article/view/18184. Acesso em: 4 aug. 2025.