@incollection{JEDP_1974____A2_0, author = {Pr\'evosto, Dominique and Rolland, Jacques}, title = {Th\'eor\`eme d'indice et r\'egularit\'e pour une classe d'op\'erateurs elliptiques et d\'eg\'en\'er\'es}, booktitle = {}, series = {Journ\'ees \'equations aux d\'eriv\'ees partielles}, eid = {2}, pages = {1--36}, publisher = {\'Ecole polytechnique}, year = {1974}, mrnumber = {51 #8631}, language = {fr}, url = {http://geodesic.mathdoc.fr/item/JEDP_1974____A2_0/} }