@article{BSMF_1908__36__129_0,
     author = {Le Roux, J.},
     title = {Sur les caract\'eristiques des syst\`emes d'\'equations aux d\'eriv\'ees partielles},
     journal = {Bulletin de la Soci\'et\'e Math\'ematique de France},
     pages = {129--133},
     publisher = {Soci\'et\'e math\'ematique de France},
     volume = {36},
     year = {1908},
     doi = {10.24033/bsmf.822},
     language = {fr},
     url = {http://www.numdam.org/articles/10.24033/bsmf.822/}
}