@article{GDZPPN002063697,
title = {Schwarzian derivatives, the Poincar\'e metric and the kernel function.},
journal = {Commentarii mathematici Helvetici},
volume = {55},
year = {1980},
pages = {50-64},
zbl = {0438.30014},
url = {http://dml.mathdoc.fr/item/GDZPPN002063697}
}
Gehring, F.W.; Beardon, A.F. Schwarzian derivatives, the Poincaré metric and the kernel function.. Commentarii mathematici Helvetici, Tome 55 (1980) pp. 50-64. http://gdmltest.u-ga.fr/item/GDZPPN002063697/