@article{1183516108, author = {Bourgin, D. G.}, title = {Classes of transformations and bordering transformations}, journal = {Bull. Amer. Math. Soc.}, volume = {57}, number = {6}, year = {1951}, pages = { 223-237}, language = {en}, url = {http://dml.mathdoc.fr/item/1183516108} }
Bourgin, D. G. Classes of transformations and bordering transformations. Bull. Amer. Math. Soc., Tome 57 (1951) no. 6, pp. 223-237. http://gdmltest.u-ga.fr/item/1183516108/