@inproceedings{pekka1980quasiconformal,
title={Quasiconformal extension of quasisymmetric mappings compatible with a Möbius group},
author={Pekka Tukia},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203303855189367},
booktitle={Acta Mathematica},
volume={154},
number={3},
pages={153-193},
year={1980},
}
Pekka Tukia. Quasiconformal extension of quasisymmetric mappings compatible with a Möbius group. 1980. Vol. 154. In Acta Mathematica. pp.153-193. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203303855189367.