@article{1183503457,
author = {Eilenberg, Samuel},
title = {An invariance theorem for subsets of $S^n$},
journal = {Bull. Amer. Math. Soc.},
volume = {47},
number = {11},
year = {1941},
pages = { 73-75},
language = {en},
url = {http://dml.mathdoc.fr/item/1183503457}
}
Eilenberg, Samuel. An invariance theorem for subsets of $S^n$. Bull. Amer. Math. Soc., Tome 47 (1941) no. 11, pp. 73-75. http://gdmltest.u-ga.fr/item/1183503457/