@article{datafreeknowledgetransferasurvey,
  title = {Data-Free Knowledge Transfer: A Survey},
  author = {Yuang Liu and Wei zhang and Jun Wang and Jianyong Wang},
  year = {2021},
  eprint = {2112.15278},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2112.15278v1},
}