@article{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},
     journal = {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/}
}