@inproceedings{jiaqi2013the,
  title={The solvability of negative Pell equation},
  author={Jiaqi Wang, and Lide Cai},
  url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20160818150522468453241},
  booktitle={Dongrun-Yau Science Award},
  year={2013},
}