@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/