@InProceedings{loper-bird:2002:ACL02-ETMTNLP,
  author    = {Edward Loper  and  Steven Bird},
  title     = {NLTK: The Natural Language Toolkit},
  booktitle = {Proceedings of the ACL-02 Workshop on Effective Tools and Methodologies for Teaching Natural Language Processing and Computational Linguistics},
  month     = {July},
  year      = {2002},
  address   = {Philadelphia, Pennsylvania, USA},
  publisher = {Association for Computational Linguistics},
  pages     = {63--70},
  url       = {http://www.aclweb.org/anthology/W02-0109},
  doi       = {10.3115/1118108.1118117}
}