@incollection{AST_1983__107-108__169_0,
     author = {Varela, F.},
     title = {Sur l'orientation d\'efinie par une forme de {Pfaff} de classe maximale},
     booktitle = {IIIe rencontre de g\'eom\'etrie du Schnepfenried (Volume 1) - 10 - 15 mai 1982},
     series = {Ast\'erisque},
     pages = {169--173},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {107-108},
     year = {1983},
     mrnumber = {753133},
     zbl = {0538.58004},
     language = {fr},
     url = {http://www.numdam.org/item/AST_1983__107-108__169_0/}
}