@article{1183506217, author = {Valentine, F. A.}, title = {Contractions in non-Euclidean spaces}, journal = {Bull. Amer. Math. Soc.}, volume = {50}, number = {12}, year = {1944}, pages = { 710-713}, language = {en}, url = {http://dml.mathdoc.fr/item/1183506217} }
Valentine, F. A. Contractions in non-Euclidean spaces. Bull. Amer. Math. Soc., Tome 50 (1944) no. 12, pp. 710-713. http://gdmltest.u-ga.fr/item/1183506217/