@article{ASENS_1980_4_13_4_397_0,
     author = {Damlakhi, M. and Helffer, B.},
     title = {Analyticit\'e et it\`eres d'un syst\`eme de champs non elliptique},
     journal = {Annales scientifiques de l'\'Ecole Normale Sup\'erieure},
     pages = {397--403},
     publisher = {Elsevier},
     volume = {4e s{\'e}rie, 13},
     number = {4},
     year = {1980},
     doi = {10.24033/asens.1388},
     mrnumber = {82j:35039},
     zbl = {0468.35084},
     language = {fr},
     url = {http://archive.numdam.org/articles/10.24033/asens.1388/}
}