@incollection{AST_1984__118__205_0,
     author = {Phillips, D.},
     title = {The free boundary of a semilinear elliptic equation},
     booktitle = {Variational methods for equilibrum problems of fluids - Trento, 20-25 juin 1983},
     series = {Ast\'erisque},
     pages = {205--210},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {118},
     year = {1984},
     mrnumber = {761750},
     zbl = {0561.35033},
     language = {en},
     url = {http://www.numdam.org/item/AST_1984__118__205_0/}
}