@article{ueffing-ney-2007-word,
    title = "Word-Level Confidence Estimation for Machine Translation",
    author = "Ueffing, Nicola  and
      Ney, Hermann",
    journal = "Computational Linguistics",
    volume = "33",
    number = "1",
    year = "2007",
    url = "https://preview.aclanthology.org/fix-sig-urls/J07-1003/",
    doi = "10.1162/coli.2007.33.1.9",
    pages = "9--40"
}