@article{ASNSP_1959_3_13_2_115_0,
     author = {Nirenberg, L.},
     title = {On elliptic partial differential equations},
     journal = {Annali della Scuola Normale Superiore di Pisa - Scienze Fisiche e Matematiche},
     pages = {115--162},
     publisher = {Scuola normale superiore},
     volume = {Ser. 3, 13},
     number = {2},
     year = {1959},
     mrnumber = {109940},
     zbl = {0088.07601},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_1959_3_13_2_115_0/}
}