@article{SEDP_1986-1987____A14_0,
     author = {Morimoto, Y.},
     title = {Criteria for hypoellipticity},
     journal = {S\'eminaire \'Equations aux d\'eriv\'ees partielles (Polytechnique) dit aussi "S\'eminaire Goulaouic-Schwartz"},
     note = {talk:15},
     pages = {1--12},
     publisher = {Ecole Polytechnique, Centre de Math\'ematiques},
     year = {1986-1987},
     mrnumber = {920033},
     zbl = {0644.35022},
     language = {en},
     url = {http://www.numdam.org/item/SEDP_1986-1987____A14_0/}
}