@inproceedings{HorrocksTessaris02,
  author	= {Horrocks, Ian and Tessaris, Sergio},
  title		= {Querying the semantic web: a formal approach},
  booktitle	= {Proceedings of the International Semantic Web Conference 2002},
  pages		= {177--191},
  year		= {2002},
  URL		= {http://link.springer.de/link/service/series/0558/bibs/2342/23420177.htm},
  urlpage	= {http://link.springer.de/link/service/series/0558/bibs/2342/23420177.htm},
  address	= {Chia, Sardinia, Italy}
}