@article{1183525256, author = {Hirsch, Morris W.}, title = {Obstruction theories for smoothing manifolds and maps}, journal = {Bull. Amer. Math. Soc.}, volume = {69}, number = {4}, year = {1963}, pages = { 352-356}, language = {en}, url = {http://dml.mathdoc.fr/item/1183525256} }
Hirsch, Morris W. Obstruction theories for smoothing manifolds and maps. Bull. Amer. Math. Soc., Tome 69 (1963) no. 4, pp. 352-356. http://gdmltest.u-ga.fr/item/1183525256/