@article{SE_1964__6__A2_0,
     author = {Lehmann, Daniel},
     title = {Une g\'en\'eralisation de la g\'eom\'etrie du plongement},
     journal = {S\'eminaire Ehresmann. Topologie et g\'eom\'etrie diff\'erentielle},
     note = {talk:2},
     pages = {1--21},
     publisher = {Secr\'etariat math\'ematique},
     volume = {6},
     year = {1964},
     mrnumber = {175067},
     zbl = {0171.42204},
     language = {fr},
     url = {http://archive.numdam.org/item/SE_1964__6__A2_0/}
}