Y. Thanoon, Thair, and Noor Husain Abdullah. “Stability Study of Double and Spherical Pendulum”. AL-Rafidain Journal of Computer Sciences and Mathematics 9, no. 2 (December 4, 2012): 13–26. Accessed November 2, 2025. https://csmj.uomosul.edu.iq/index.php/csmj/article/view/36852.