@inproceedings{liang-etal-2015-measuring,
    title = "Measuring Prerequisite Relations Among Concepts",
    author = "Liang, Chen  and
      Wu, Zhaohui  and
      Huang, Wenyi  and
      Giles, C. Lee",
    editor = "M{\`a}rquez, Llu{\'i}s  and
      Callison-Burch, Chris  and
      Su, Jian",
    booktitle = "Proceedings of the 2015 Conference on Empirical Methods in Natural Language Processing",
    month = sep,
    year = "2015",
    address = "Lisbon, Portugal",
    publisher = "Association for Computational Linguistics",
    url = "https://preview.aclanthology.org/fix-sig-urls/D15-1193/",
    doi = "10.18653/v1/D15-1193",
    pages = "1668--1674"
}