@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}, publisher = {Ecole polytechnique}, year = {1980}, zbl = {0445.35070}, language = {fr}, url = {http://archive.numdam.org/item/JEDP_1980____A1_0/} }