@misc{jia2018dark,
  title={Dark photon portal dark matter with the 21-cm anomaly},
  author={Lian-Bao Jia},
  year={2018},
  eprint={1804.07934},
  archivePrefix={arXiv},
  primaryClass={hep-ph},
  doi={10.1140/epjc/s10052-019-6542-9},
  url={https://arxiv.org/abs/1804.07934}
}