@article{SEDP_1974-1975____A12_0,
     author = {Bolley, P. and Camus, J. and Helffer, B.},
     title = {Sur une classe d'op\'erateurs partiellement hypoelliptiques},
     journal = {S\'eminaire \'Equations aux d\'eriv\'ees partielles (Polytechnique) dit aussi "S\'eminaire Goulaouic-Schwartz"},
     note = {talk:13},
     pages = {1--16},
     publisher = {Ecole Polytechnique, Centre de Math\'ematiques},
     year = {1974-1975},
     zbl = {0309.35026},
     language = {fr},
     url = {http://www.numdam.org/item/SEDP_1974-1975____A12_0/}
}