Wang, P., Regularity of free boundaries of two-phase problems for fully nonlinear elliptic equations of second order. Part 1: Lipschitz free boundaries are C1,α, Comm. Pure Appl. Math., Vol. LIII (2000), 799-810
Lu, G. and Wang, P., Inhomogeneous Infinity Laplace Equation, Advances in Mathematics, Vol. 217, 4 (2008), 1838-1868
Lu, G. and Wang, P., On the uniqueness of a solution of a two-phase free boundary problem, Journal of Functional Analysis, Vol.258(2010), 2817-2833
Caffarelli, L.A. and Wang, P., A bifurcation phenomenon in a singularly perturbed one-phase free boundary problem of phase transition, Calculus of Variations and Partial Differential Equations, Vol 54, No.4 (2015), 3517-3529