Soliman, A. A., R. A. Sallam, and Ahmed Mohamed Hassan. “Oscillation Criteria of Second Order Nonlinear Neutral Differential Equations”. International Journal of Applied Mathematical Research 1, no. 3 (July 5, 2012): 314–322. Accessed December 22, 2024. https://sciencepubco.com/index.php/ijamr/article/view/128.