@inproceedings{cheng-etal-2021-guiding,
    title = "Guiding the Growth: Difficulty-Controllable Question Generation through Step-by-Step Rewriting",
    author = "Cheng, Yi  and
      Li, Siyao  and
      Liu, Bang  and
      Zhao, Ruihui  and
      Li, Sujian  and
      Lin, Chenghua  and
      Zheng, Yefeng",
    editor = "Zong, Chengqing  and
      Xia, Fei  and
      Li, Wenjie  and
      Navigli, Roberto",
    booktitle = "Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language Processing (Volume 1: Long Papers)",
    month = aug,
    year = "2021",
    address = "Online",
    publisher = "Association for Computational Linguistics",
    url = "https://aclanthology.org/2021.acl-long.465/",
    doi = "10.18653/v1/2021.acl-long.465",
    pages = "5968--5978"
}