@article{CTGDC_1982__23_1_55_0,
     author = {Libermann, Paulette},
     title = {Remarques sur les syst\`emes diff\'erentiels},
     journal = {Cahiers de topologie et g\'eom\'etrie diff\'erentielle},
     pages = {55--72},
     year = {1982},
     publisher = {Dunod \'editeur, publi\'e avec le concours du CNRS},
     volume = {23},
     number = {1},
     mrnumber = {648796},
     zbl = {0481.58005},
     language = {fr},
     url = {https://www.numdam.org/item/CTGDC_1982__23_1_55_0/}
}