@incollection{JEDP_1980____A17_0,
     author = {Sebbar, Ahmed},
     title = {Prolongement des solutions d'un op\'erateur diff\'erentiel d'ordre infini},
     booktitle = {},
     series = {Journ\'ees \'equations aux d\'eriv\'ees partielles},
     eid = {17},
     pages = {1--5},
     publisher = {Ecole polytechnique},
     year = {1980},
     zbl = {0449.35014},
     language = {fr},
     url = {http://archive.numdam.org/item/JEDP_1980____A17_0/}
}