@article{1183510414,
author = {Gottschalk, W. H.},
title = {On $k$-to-1 transformations},
journal = {Bull. Amer. Math. Soc.},
volume = {53},
number = {12},
year = {1947},
pages = { 168-169},
language = {en},
url = {http://dml.mathdoc.fr/item/1183510414}
}
Gottschalk, W. H. On $k$-to-1 transformations. Bull. Amer. Math. Soc., Tome 53 (1947) no. 12, pp. 168-169. http://gdmltest.u-ga.fr/item/1183510414/