@article{1183522993, author = {Hermann, Robert}, title = {Secondary obstructions for fibre spaces}, journal = {Bull. Amer. Math. Soc.}, volume = {65}, number = {6}, year = {1959}, pages = { 5-8}, language = {en}, url = {http://dml.mathdoc.fr/item/1183522993} }
Hermann, Robert. Secondary obstructions for fibre spaces. Bull. Amer. Math. Soc., Tome 65 (1959) no. 6, pp. 5-8. http://gdmltest.u-ga.fr/item/1183522993/