@inproceedings{stephen1981a,
title={A geometric proof of Mostow's rigidity theorem for groups of divergence type},
author={Stephen Agard},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203300269416342},
booktitle={Acta Mathematica},
volume={151},
number={1},
pages={231-252},
year={1981},
}
Stephen Agard. A geometric proof of Mostow's rigidity theorem for groups of divergence type. 1981. Vol. 151. In Acta Mathematica. pp.231-252. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203300269416342.