@article{SEDP_2005-2006____A14_0,
     author = {Journ\'e, Jean-Lin and Tr\'epreau, Jean-Marie},
     title = {Hypoellipticit\'e sans sous-ellipticit\'e~: le cas des syst\`emes de $n$ champs de vecteurs complexes en $(n+1)$ variables},
     journal = {S\'eminaire \'Equations aux d\'eriv\'ees partielles (Polytechnique) dit aussi "S\'eminaire Goulaouic-Schwartz"},
     note = {talk:14},
     pages = {1--17},
     publisher = {Centre de math\'ematiques Laurent Schwartz, \'Ecole polytechnique},
     year = {2005-2006},
     mrnumber = {2276079},
     language = {fr},
     url = {http://archive.numdam.org/item/SEDP_2005-2006____A14_0/}
}