1. User's guide to viscosity solutions of second order partial differential equations;Crandall;Bull. Amer. Math. Soc.,1992
2. Controlled Markov Processes and Viscosity Solutions;Fleming,2006
3. Elliptic Partial Differential Equations of Second Order;Gilbarg,1983
4. Dynamic Optimization;Kamien,1991
5. Brownian Motion and Stochastic Calculus;Karatzas,1991