Al-Hawasy, Jamil A., and Doaa Kateb Jasim. “The Continuous Classical Optimal Control Problems for Triple Nonlinear Elliptic Boundary Value Problem”. Ibn AL- Haitham Journal For Pure and Applied Sciences 33, no. 3 (July 20, 2020): 101–112. Accessed May 25, 2022. https://jih.uobaghdad.edu.iq/index.php/j/article/view/2477.