@inproceedings{ruder2019transfer,
  title={Transfer Learning in Natural Language Processing},
  author={Ruder, Sebastian and Peters, Matthew E and Swayamdipta, Swabha and Wolf, Thomas},
  booktitle={Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Tutorials},
  pages={15--18},
  year={2019}
}