Abdulkareem, Noor Abdulameer, Tongxing Li, and Hussain Ali Mohamad. “Oscillation and Asymptotic Behavior of Solution of Nth Order System Nonlinear of Neutral Differential Equation”. Journal of Al-Qadisiyah for Computer Science and Mathematics 12, no. 1 (February 23, 2020): Math Page 72 – 82. Accessed December 21, 2024. https://jqcsm.qu.edu.iq/index.php/journalcm/article/view/669.