@inproceedings{li-2009-use,
    title = "On the Use of Virtual Evidence in Conditional Random Fields",
    author = "Li, Xiao",
    editor = "Koehn, Philipp  and
      Mihalcea, Rada",
    booktitle = "Proceedings of the 2009 Conference on Empirical Methods in Natural Language Processing",
    month = aug,
    year = "2009",
    address = "Singapore",
    publisher = "Association for Computational Linguistics",
    url = "https://preview.aclanthology.org/fix-sig-urls/D09-1134/",
    pages = "1289--1297"
}