V. P. Maslov and S. N. Samborsky, “Boundary-value problems for stationary Hamilton-Jacobi and Bellman equations”, Ukr. Mat. Zhurn., vol. 49, no. 3, pp. 433–447, Mar. 1997, Accessed: Apr. 13, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/5016