@inproceedings{dexingtime-periodic,
title={Time-periodic solutions of the Einsteins field equations III: physical singularities},
author={DeXing Kong, Kefeng Liu, and Ming Shen},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191221111457415598649},
booktitle={Science China Mathematics},
volume={54},
number={1},
pages={23-33},
}

DeXing Kong, Kefeng Liu, and Ming Shen. Time-periodic solutions of the Einsteins field equations III: physical singularities. Vol. 54. In Science China Mathematics. pp.23-33. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20191221111457415598649.