@article{1183499749, author = {Carath\'eodory, Constantin}, title = {A generalization of Schwarz's Lemma}, journal = {Bull. Amer. Math. Soc.}, volume = {43}, number = {12}, year = {1937}, pages = { 231-241}, language = {en}, url = {http://dml.mathdoc.fr/item/1183499749} }
Carathéodory, Constantin. A generalization of Schwarz's Lemma. Bull. Amer. Math. Soc., Tome 43 (1937) no. 12, pp. 231-241. http://gdmltest.u-ga.fr/item/1183499749/