@inproceedings{jinxin2020non-collision,
title={Non-collision singularities in a planar 4-body problem},
author={Jinxin Xue},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20220310102731288247913},
booktitle={Acta Mathematica},
volume={224},
number={2},
pages={253-388},
year={2020},
}