@incollection{JEDP_1980____A1_0,
     author = {Alinhac, Serge and Zuily, Claude},
     title = {Unicit\'e et non unicit\'e du probl\`eme de {Cauchy} pour des op\'erateurs hyperboliques \`a caract\'eristiques doubles},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {1},
     pages = {1--5},
     year = {1980},
     publisher = {Ecole polytechnique},
     doi = {10.5802/jedp.205},
     zbl = {0445.35070},
     language = {fr},
     url = {https://www.numdam.org/articles/10.5802/jedp.205/}
}