@inproceedings{simon2014a,
title={A Gibbons-Penrose inequality for surfaces in Schwarzschild spacetime},
author={Simon Brendle, and Mu-Tao Wang},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20160820154307709913327},
booktitle={Communications in Mathematical Physics},
volume={330},
number={1},
pages={33–43},
year={2014},
}

Simon Brendle, and Mu-Tao Wang. A Gibbons-Penrose inequality for surfaces in Schwarzschild spacetime. 2014. Vol. 330. In Communications in Mathematical Physics. pp.33–43. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20160820154307709913327.