@article{unsupervisedopendomainquestionanswering,
  title = {Unsupervised Open-Domain Question Answering},
  author = {Pengfei Zhu and Xiaoguang Li and Jian Li and Hai Zhao},
  year = {2021},
  eprint = {2108.13817},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2108.13817v1},
}