@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/