Abdullah Manna, Saad, and Norjan Hasan Juma. “Stability Analysis of Steady State Solutions of Sine–Gordon Equation”. AL-Rafidain Journal of Computer Sciences and Mathematics 4, no. 2 (December 3, 2007): 11–29. Accessed December 18, 2025. https://csmj.uomosul.edu.iq/index.php/csmj/article/view/36676.