Al-hawasy, J. A. and Al-Qaisi, S. J. M. (2019) “The Continuous Classical Boundary Optimal Control of a Couple Nonlinear Elliptic Partial Differential Equations with State Constraints”, Al-Mustansiriyah Journal of Science, 30(1), pp. 143–151. doi: 10.23851/mjs.v30i1.464.