@article{ASNSP_1979_4_6_4_561_0,
     author = {Lewy, Hans},
     title = {An inversion of the obstacle problem and its explicit solution},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {561--571},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 6},
     number = {4},
     year = {1979},
     mrnumber = {563334},
     zbl = {0428.35080},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_1979_4_6_4_561_0/}
}