@article{MAN_1996__305_2_182999,
     author = {Joachim Escher and Gieri Simonett},
     title = {Analyticity of the interface in a free boundary problem.},
     journal = {Mathematische Annalen},
     pages = {439--460},
     publisher = {mathdoc},
     volume = {305},
     number = {2},
     year = {1996},
     zbl = {0857.76086},
     url = {http://geodesic.mathdoc.fr/item/MAN_1996__305_2_182999/}
}