@inproceedings{bird-liberman-1999-annotation,
    title = "Annotation Graphs as a Framework for Multidimensional Linguistic Data Analysis",
    author = "Bird, Steven  and
      Liberman, Mark",
    booktitle = "Towards Standards and Tools for Discourse Tagging",
    year = "1999",
    url = "https://preview.aclanthology.org/jlcl-multiple-ingestion/W99-0301/"
}