@misc{li2019federated,
  title={Federated Learning: Challenges, Methods, and Future Directions},
  author={Tian Li and Anit Kumar Sahu and Ameet Talwalkar and Virginia Smith},
  year={2019},
  eprint={1908.07873},
  archivePrefix={arXiv},
  primaryClass={cs.LG},
  doi={10.1109/MSP.2020.2975749},
  url={https://arxiv.org/abs/1908.07873}
}