@incollection{MSMF_1972__31-32__35_0,
     author = {Baouendi, Mohamed Salah},
     title = {It\'er\'es d'op\'erateurs elliptiques d\'eg\'en\'er\'es et applications},
     booktitle = {Colloque d'analyse fonctionnelle (Bordeaux, 1971)},
     series = {M\'emoires de la Soci\'et\'e Math\'ematique de France},
     pages = {35--38},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {31-32},
     year = {1972},
     doi = {10.24033/msmf.61},
     mrnumber = {50 #8160},
     zbl = {0276.35049},
     url = {http://www.numdam.org/articles/10.24033/msmf.61/}
}