@incollection{JEDP_1978____A2_0, author = {Johannes Sj\"ostrand}, title = {Valeurs propres pour des op\'erateurs hypoelliptique}, booktitle = {}, series = {Journ\'ees \'equations aux d\'eriv\'ees partielles}, eid = {2}, pages = {1--2}, publisher = {\'Ecole polytechnique}, year = {1978}, doi = {10.5802/jedp.170}, language = {fr}, url = {https://proceedings.centre-mersenne.org/articles/10.5802/jedp.170/} }