Gasim Salim, Abdulghafoor, and Raad Awad Alhamdani. “Studying the Stability of Some Models Combinatory With Application”. AL-Rafidain Journal of Computer Sciences and Mathematics 7, no. 2 (June 3, 2010): 139–157. Accessed December 18, 2025. https://csmj.uomosul.edu.iq/index.php/csmj/article/view/36356.