@inproceedings{bing-long2020on,
title={On Euler characteristic and fundamental groups of compact manifolds},
author={Bing-Long Chen, and Xiaokui Yang},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20220622154552520091447},
booktitle={Mathematische Annalen},
volume={381},
pages={1723–1743},
year={2020},
}

Bing-Long Chen, and Xiaokui Yang. On Euler characteristic and fundamental groups of compact manifolds. 2020. Vol. 381. In Mathematische Annalen. pp.1723–1743. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20220622154552520091447.