@article{journals/corr/cs-DB-9812022,
  title = "Hypertree Decompositions and Tractable Queries",
  author = "Georg Gottlob and Nicola Leone and Francesco Scarcello",
  year = "1998",
  journal = "{CoRR}",
  url = "http://arxiv.org/abs/cs.DB/9812022",
  volume = "cs.DB/9812022",
}