@article{AIF_1965__15_2_225_0,
     author = {Vaillant, Jean},
     title = {Caract\'eristiques multiples et bicaract\'eristiques des syst\`emes d'\'equations aux d\'eriv\'ees partielles lin\'eaires et \`a coefficients constants},
     journal = {Annales de l'Institut Fourier},
     pages = {225--311},
     publisher = {Institut Fourier},
     address = {Grenoble},
     volume = {15},
     number = {2},
     year = {1965},
     doi = {10.5802/aif.215},
     mrnumber = {32 #7919},
     zbl = {0139.05304},
     language = {fr},
     url = {http://www.numdam.org/articles/10.5802/aif.215/}
}