@incollection{JEDP_1975____93_0, author = {Boutet de Monvel, Louis and Grigis, Alain and Helffer, Bernard}, title = {Param\'etrixes d'op\'erateurs pseudo-diff\'erentiels \`a caract\'eristiques multiples}, booktitle = {}, series = {Journ\'ees \'equations aux d\'eriv\'ees partielles}, pages = {93--121}, publisher = {Ecole polytechnique}, year = {1975}, mrnumber = {58 #12046}, language = {fr}, url = {http://www.numdam.org/item/JEDP_1975____93_0/} }