@inproceedings{mario2000quasiregular,
title={Quasiregular mapping and cohomology},
author={Mario Bonk, and Juha Heinonen},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203338137680608},
booktitle={Acta Mathematica},
volume={186},
number={2},
pages={219-238},
year={2000},
}