@incollection{JEDP_1975____251_0, author = {Nourrigat, Jean-Fran\c{c}ois}, 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 = {http://archive.numdam.org/item/JEDP_1975____251_0/} }