@article{1077489916,
author = {Whitney, Hassler},
title = {On the maps of an $n$ -sphere into another $n$ -sphere},
journal = {Duke Math. J.},
volume = {3},
number = {1},
year = {1937},
pages = { 46-50},
language = {en},
url = {http://dml.mathdoc.fr/item/1077489916}
}
Whitney, Hassler. On the maps of an $n$ -sphere into another $n$ -sphere. Duke Math. J., Volume 3 (1937) no. 1, pp. 46-50. http://gdmltest.u-ga.fr/item/1077489916/