@inproceedings{lars1963quasiconformal,
title={Quasiconformal reflections},
author={Lars V. Ahlfors},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203201383718956},
booktitle={Acta Mathematica},
volume={109},
number={1},
pages={291-301},
year={1963},
}