Al-Hawasy J, Haider H. Diwan, Waffa F. Keidan. Constraints Optimal Control Problem For Quaternary Nonlinear Elliptic System. Acad. Sci. J. [Internet]. 2024 Jul. 1 [cited 2025 Sep. 29];2(3):1-15. Available from: http://acadscij.uodiyala.edu.iq/index.php/Home/article/view/81