Groupes d'homotopie
Séminaire Henri Cartan, Tome 2 (1949-1950), Exposé no. 2, p. 1-7
@article{SHC_1949-1950__2__A2_0,
     author = {Serre, Jean-Pierre},
     title = {Groupes d'homotopie},
     journal = {S\'eminaire Henri Cartan},
     publisher = {Secr\'etariat math\'ematique},
     volume = {2},
     year = {1949-1950},
     note = {talk:2},
     pages = {1-7},
     language = {fr},
     url = {http://http://www.numdam.org/item/SHC_1949-1950__2__A2_0}
}
Serre, J-P. Groupes d'homotopie. Séminaire Henri Cartan, Tome 2 (1949-1950) Exposé no. 2, pp. 1-7. http://www.numdam.org/item/SHC_1949-1950__2__A2_0/

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