@article{BSMA_1882_2_6_1_49_1,
     author = {Darboux, G.},
     title = {Sur le probl\`eme de {Pfaff}},
     journal = {Bulletin des Sciences Math\'ematiques et Astronomiques},
     pages = {49--68},
     publisher = {Gauthier-Villars},
     volume = {2e s{\'e}rie, 6},
     number = {1},
     year = {1882},
     language = {fr},
     url = {http://www.numdam.org/item/BSMA_1882_2_6_1_49_1/}
}