@article{neuralmachinetranslationchallenges,
  title = {Neural Machine Translation: Challenges, Progress and Future},
  author = {Jiajun Zhang and Cheng-qing Zong},
  year = {2020},
  eprint = {2004.05809},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2004.05809v1},
}