@inproceedings{multilevelpolicyandrewardreinforcement,
  title = {Multi-Level Policy and Reward Reinforcement Learning for Image Captioning},
  author = {An-An Liu1 and Ning Xu1 and Hanwang Zhang2 and Weizhi Nie1 and Yuting Su1 and Yongdong Zhang},
  year = {2018},
  booktitle = {IJCAI 2018 6},
  url = {https://www.ijcai.org/proceedings/2018/0114.pdf},
}