@inproceedings{PeHM09a,
  title = "Efficient Query Answering for {OWL} 2",
  author = "H\'{e}ctor P\'{e}rez-Urbina and Ian Horrocks and Boris Motik",
  year = "2009",
  booktitle = "Proc.\ of the 8th International Semantic Web Conference (ISWC 2009)",
  pages = "489--504",
  publisher = "Springer",
  series = "Lecture Notes in Computer Science",
  url = "download/2009/PeHM09a.pdf",
  volume = "5823",
}