@article{johnson-kay-1994-parsing,
    title = "Parsing and empty nodes",
    author = "Johnson, Mark  and
      Kay, Martin",
    editor = "Hirschberg, Julia",
    journal = "Computational Linguistics",
    volume = "20",
    number = "2",
    year = "1994",
    address = "Cambridge, MA",
    publisher = "MIT Press",
    url = "https://preview.aclanthology.org/fix-sig-urls/J94-2005/",
    pages = "289--300"
}