@incollection{JEDP_1975____251_0,
     author = {Jean-Fran\c{c}ois Nourrigat},
     title = {Probl\`emes mixtes pour des syst\`emes hyperboliques singuliers},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     pages = {251--261},
     publisher = {\'Ecole polytechnique},
     year = {1975},
     mrnumber = {509847},
     language = {fr},
     url = {https://proceedings.centre-mersenne.org/item/JEDP_1975____251_0/}
}