@article{ASNSP_1976_4_3_1_1_0,
     author = {Treves, Fran\c{c}ois},
     title = {Integral representation of solutions of first-order linear partial differential equations, {I}},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {1--35},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 3},
     number = {1},
     year = {1976},
     mrnumber = {399635},
     language = {en},
     url = {http://archive.numdam.org/item/ASNSP_1976_4_3_1_1_0/}
}