@article{SJL_1973-1977___1_A5_0,
     author = {Berzin, Robert and Vaillant, Jean},
     title = {Param\'etrix du probl\`eme de {Cauchy} pour un syst\`eme faiblement hyperbolique \`a caract\'eristiques multiples},
     journal = {S\'eminaire sur les \'equations aux d\'eriv\'ees partielles},
     note = {talk:5},
     pages = {1--8},
     year = {1973-1977},
     publisher = {Coll\`ege de France},
     number = {1},
     language = {fr},
     url = {https://www.numdam.org/item/SJL_1973-1977___1_A5_0/}
}