@article{EJDE_2006__2006__a2,
     author = {Gripenberg,  Gustaf},
     title = {Generalized viscosity solutions of elliptic {PDEs} and boundary conditions},
     journal = {Electronic journal of differential equations},
     year = {2006},
     volume = {2006},
     zbl = {1166.35330},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2006__2006__a2/}
}