@inproceedings{tadeusz1990quasiregular,
title={Quasiregular mappings in even dimensions},
author={Tadeusz Iwaniec, and Gaven Martin},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203319202601478},
booktitle={Acta Mathematica},
volume={170},
number={1},
pages={29-81},
year={1990},
}