@article{EJDE_2015__2015__a83,
     author = {Saadi,  Abderachid},
     title = {Continuity of the free boundary in elliptic problems with {Neumann} boundary condition},
     journal = {Electronic journal of differential equations},
     year = {2015},
     volume = {2015},
     zbl = {1322.35014},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2015__2015__a83/}
}