@article{journals/corr/cs-DB-0211020,
  title = "Monadic Datalog and the Expressive Power of Languages for Web Information Extraction",
  author = "Georg Gottlob and Christoph Koch",
  year = "2002",
  journal = "{CoRR}",
  url = "http://arxiv.org/abs/cs.DB/0211020",
  volume = "cs.DB/0211020",
}