%0 Journal Article %A F.W. Gehring %A A.F. Beardon %T Schwarzian derivatives, the Poincaré metric and the kernel function. %J Commentarii mathematici Helvetici %D 1980 %P 50-64 %V 55 %I mathdoc %U http://geodesic.mathdoc.fr/item/CMH_1980__55_139813/ %F CMH_1980__55_139813