@inproceedings{peter1980quasiconformal,
title={Quasiconformal mappings and extendability of functions in sobolev spaces},
author={Peter W. Jones},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203254860308301},
booktitle={Acta Mathematica},
volume={147},
number={1},
pages={71-88},
year={1980},
}
Peter W. Jones. Quasiconformal mappings and extendability of functions in sobolev spaces. 1980. Vol. 147. In Acta Mathematica. pp.71-88. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203254860308301.