中国科学院数学与系统科学研究院期刊网
AMS
Inequalities on the Inner Radius of Univalency and the Norm of Pre-Schwarzian Derivative
Tao CHENG, Yue Ming KANG, Ji Xiu CHEN
Acta Mathematica Sinica . 2009, (1): 59 -64 .  DOI: 10.1007/s10114-008-6519-3