@conference{MaKHIJCAR2010,
  title = "Tractabe Extensions of the Description Logic EL with Numerical Datatypes.",
  author = "Despoina Magka and Yevgeny Kazakov and Ian Horrocks.",
  year = "2010",
  howpublished = "Int. Joint Conf. on Automated Reasoning (IJCAR 2010)",
  journal = "Int. Joint Conf. on Automated Reasoning (IJCAR 2010)",
}