@article{Huang2020Challenges,
title={Challenges in building intelligent open-domain dialog systems},
author={Huang, Minlie and Zhu, Xiaoyan and Gao, Jianfeng},
journal={ACM Transactions on Information Systems (TOIS)},
volume={38},
number={3},
pages={1--32},
year={2020},
publisher={ACM New York, NY, USA}
}