@article{190807873,
  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},
  url = {https://arxiv.org/abs/1908.07873v1},
}