Dymkov, Michael P., and Siarhey M. Dymkou. “A Method for Relaxing State Constraints in Nonsmooth Optimal Control Problems”. Journal of the Belarusian State University. Mathematics and Informatics, no. 2 (July 15, 2022): 107–114. Accessed July 17, 2026. https://journals.bsu.by/index.php/mathematics/article/view/4715.