@article{1077471790,
author = {Civin, Paul},
title = {Two-to-one mappings of manifolds},
journal = {Duke Math. J.},
volume = {10},
number = {1},
year = {1943},
pages = { 49-57},
language = {en},
url = {http://dml.mathdoc.fr/item/1077471790}
}
Civin, Paul. Two-to-one mappings of manifolds. Duke Math. J., Tome 10 (1943) no. 1, pp. 49-57. http://gdmltest.u-ga.fr/item/1077471790/