Abdullah Manna, S., سعد, N. Hasan Juma, and نورجان. “Stability Analysis of Steady State Solutions of Sine–Gordon Equation”. AL-Rafidain Journal of Computer Sciences and Mathematics, vol. 4, no. 2, June 2025, pp. 11-29, https://rjps.uomosul.edu.iq/index.php/csmj/article/view/19639.