@article{05237143, title = {Subsolutions of elliptic operators in divergence form and application to two-phase free boundary problems.}, journal = {Boundary Value Problems [electronic only]}, volume = {2007}, year = {2007}, doi = {10.1155/2007/57049}, zbl = {1188.35070}, language = {en}, url = {http://dml.mathdoc.fr/item/05237143} }
Ferrari, Fausto; Salsa, Sandro. Subsolutions of elliptic operators in divergence form and application to two-phase free boundary problems.. Boundary Value Problems [electronic only], Tome 2007 (2007) . doi : 10.1155/2007/57049. http://gdmltest.u-ga.fr/item/05237143/