Danilov, V. Ya., et al. “Viscous Solutions for the Hamilton – Jacobi – Bellman Equation on Time Scales”. Ukrains’kyi Matematychnyi Zhurnal, vol. 69, no. 7, July 2017, pp. 933-50, https://umj.imath.kiev.ua/index.php/umj/article/view/1747.