@article{JRAM_1981__325_152360,
     author = {H.W. Alt and L.A. Caffarelli},
     title = {Existence and regularity for a minimum problem with free boundary.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {105--144},
     publisher = {mathdoc},
     volume = {325},
     year = {1981},
     zbl = {0449.35105},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1981__325_152360/}
}