@inproceedings{chiu-chu2003positivity,
title={Positivity of quasilocal mass},
author={Chiu-Chu Melissa Liu, and Shing-Tung Yau},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191224203616995232061},
booktitle={Physical review letters},
volume={90},
number={23},
pages={231102},
year={2003},
}
Chiu-Chu Melissa Liu, and Shing-Tung Yau. Positivity of quasilocal mass. 2003. Vol. 90. In Physical review letters. pp.231102. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191224203616995232061.