@article{ASNSP_1997_4_25_1-2_299_0,
     author = {Dacorogna, Bernard and Marcellini, Paolo},
     title = {Implicit second order partial differential equations},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {299--328},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 25},
     number = {1-2},
     year = {1997},
     mrnumber = {1655520},
     zbl = {1003.35043},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1997_4_25_1-2_299_0/}
}