Sur les deuxièmes obstructions
Séminaire Ehresmann. Topologie et géométrie différentielle, Volume 1  (1957-1958), Talk no. 13, 13 p.
@article{SE_1957-1958__1__A5_0,
     author = {de Cahvalho, Carlos A. A.},
     title = {Sur les deuxi\`emes obstructions},
     journal = {S\'eminaire Ehresmann. Topologie et g\'eom\'etrie diff\'erentielle},
     publisher = {Secr\'etariat math\'ematique},
     volume = {1},
     year = {1957-1958},
     note = {talk:13},
     zbl = {0158.42003},
     language = {fr},
     url = {http://www.numdam.org/item/SE_1957-1958__1__A5_0}
}
de Cahvalho, Carlos A. A. Sur les deuxièmes obstructions. Séminaire Ehresmann. Topologie et géométrie différentielle, Volume 1 (1957-1958) , Talk no. 13, 13 p. http://www.numdam.org/item/SE_1957-1958__1__A5_0/

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