J. Hasan, Waleed, and Kasim A. Hussain. 2022. “Fifth Order Improved Runge-Kutta Nystrom Method Using Trigonometrically-Fitting for Solving Oscillatory Problems”. Al-Nahrain Journal of Science 25 (4): 63-67. https://mail.anjs.edu.iq/index.php/anjs/article/view/2517.