Aisagaliev, S. A., and A. A. Kabidoldanova. “Boundary Value Optimal Control Problems With Quadratic Functional and With the Account of Resource Restraint for Linear Systems”. Journal of Mathematics, Mechanics and Computer Science, vol. 71, no. 4, Dec. 2011, pp. 32-40, https://bm.kaznu.kz/index.php/kaznu/article/view/217.