Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{CMH_1961__35_139201, author = {Israel Berstein}, title = {Homotopy mod. {C} of {Spaces} of {Category} 2.}, journal = {Commentarii mathematici Helvetici}, pages = {9--14}, publisher = {mathdoc}, volume = {35}, year = {1961}, zbl = {0095.16901}, url = {http://geodesic.mathdoc.fr/item/CMH_1961__35_139201/} }
Israel Berstein. Homotopy mod. C of Spaces of Category 2.. Commentarii mathematici Helvetici, Tome 35 (1961), pp. 9-14. http://geodesic.mathdoc.fr/item/CMH_1961__35_139201/