@article{SEDP_1991-1992____A22_0,
     author = {Cancelier, C. E. and Chemin, J.-Y. and Xu, C. J.},
     title = {Calcul de {Weyl} et op\'erateurs sous-elliptiques},
     journal = {S\'eminaire \'Equations aux d\'eriv\'ees partielles (Polytechnique) dit aussi "S\'eminaire Goulaouic-Schwartz"},
     note = {talk:22},
     pages = {1--14},
     publisher = {Ecole Polytechnique, Centre de Math\'ematiques},
     year = {1991-1992},
     mrnumber = {1226501},
     language = {fr},
     url = {http://www.numdam.org/item/SEDP_1991-1992____A22_0/}
}