@incollection{JEDP_1974____A2_0, author = {Dominique Pr\'evosto and Jacques Rolland}, 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 = {https://proceedings.centre-mersenne.org/item/JEDP_1974____A2_0/} }