@article{GDZPPN002418983, title = {Lipschitz Continuous Solutions for Nonlinear Obstacle Problems.}, journal = {Mathematische Zeitschrift}, volume = {154}, year = {1977}, pages = {51-66}, zbl = {0351.35028}, url = {http://dml.mathdoc.fr/item/GDZPPN002418983} }
Williams, Graham H. Lipschitz Continuous Solutions for Nonlinear Obstacle Problems.. Mathematische Zeitschrift, Tome 154 (1977) pp. 51-66. http://gdmltest.u-ga.fr/item/GDZPPN002418983/