Maslov, V. P., and S. N. Samborsky. “Boundary-Value Problems for Stationary Hamilton-Jacobi and Bellman Equations”. Ukrains’kyi Matematychnyi Zhurnal 49, no. 3 (March 25, 1997): 433–447. Accessed December 5, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/5016.