@article{SEDP_1971-1972____A4_0,
     author = {Derridj, M. and Zuily, C.},
     title = {R\'egularit\'e {Gevrey} pour les op\'erateurs de {H\"ormander}},
     journal = {S\'eminaire \'Equations aux d\'eriv\'ees partielles (Polytechnique) dit aussi "S\'eminaire Goulaouic-Schwartz"},
     note = {talk:4},
     pages = {1--10},
     publisher = {Ecole Polytechnique, Centre de Math\'ematiques},
     year = {1971-1972},
     mrnumber = {407434},
     zbl = {0242.35019},
     language = {fr},
     url = {http://archive.numdam.org/item/SEDP_1971-1972____A4_0/}
}