@article{MaKHJAR2011,
  title = "Tractable Extensions of the Description Logic EL with Numerical Datatypes",
  author = "Despoina Magka‚ Yevgeny Kazakov and Ian Horrocks",
  year = "2011",
  booktitle = "Journal of Automated Reasoning",
  journal = "Journal of Automated Reasoning",
  number = "4",
  pages = "427--450",
  volume = "47",
}