Qarawani, Maher Nazmi. “Hyers-Ulam Stability of Linear and Nonlinear Differential Equations of Second Order”. International Journal of Applied Mathematical Research 1, no. 4 (August 31, 2012): 422–432. Accessed April 17, 2025. https://sciencepubco.com/index.php/ijamr/article/view/160.