@inproceedings{ehara-etal-2012-mining,
    title = "Mining Words in the Minds of Second Language Learners: Learner-Specific Word Difficulty",
    author = "Ehara, Yo  and
      Sato, Issei  and
      Oiwa, Hidekazu  and
      Nakagawa, Hiroshi",
    editor = "Kay, Martin  and
      Boitet, Christian",
    booktitle = "Proceedings of {COLING} 2012",
    month = dec,
    year = "2012",
    address = "Mumbai, India",
    publisher = "The COLING 2012 Organizing Committee",
    url = "https://preview.aclanthology.org/fix-sig-urls/C12-1049/",
    pages = "799--814"
}