@incollection{JEDP_1986____A3_0,
     author = {Wagschal, Claude},
     title = {Probl\`eme de {Cauchy} ramifi\'e \`a caract\'eristiques tangentes},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {3},
     pages = {1--8},
     year = {1986},
     publisher = {Ecole polytechnique},
     doi = {10.5802/jedp.308},
     mrnumber = {874545},
     zbl = {0627.35012},
     language = {fr},
     url = {https://www.numdam.org/articles/10.5802/jedp.308/}
}