@inproceedings{martens-2009-quantitative,
    title = "Quantitative analysis of treebanks using frequent subtree mining methods",
    author = "Martens, Scott",
    editor = "Choudhury, Monojit  and
      Hassan, Samer  and
      Mukherjee, Animesh  and
      Muresan, Smaranda",
    booktitle = "Proceedings of the 2009 Workshop on Graph-based Methods for Natural Language Processing ({T}ext{G}raphs-4)",
    month = aug,
    year = "2009",
    address = "Suntec, Singapore",
    publisher = "Association for Computational Linguistics",
    url = "https://preview.aclanthology.org/fix-sig-urls/W09-3212/",
    pages = "84--92"
}