@article{luan-etal-2021-sparse,
    title = "Sparse, Dense, and Attentional Representations for Text Retrieval",
    author = "Luan, Yi  and
      Eisenstein, Jacob  and
      Toutanova, Kristina  and
      Collins, Michael",
    editor = "Roark, Brian  and
      Nenkova, Ani",
    journal = "Transactions of the Association for Computational Linguistics",
    volume = "9",
    year = "2021",
    address = "Cambridge, MA",
    publisher = "MIT Press",
    url = "https://aclanthology.org/2021.tacl-1.20/",
    doi = "10.1162/tacl_a_00369",
    pages = "329--345"
}