Hameed, Amal S., and Radhi A. Zaboon. “Approximate Solutions for Optimal Control of Fixed Boundary Value Problems Using Variational and Minimum Approaches”. Al-Mustansiriyah Journal of Science, vol. 34, no. 3, Sept. 2023, pp. 72-85, https://doi.org/10.23851/mjs.v34i3.1104.