@mastersthesis{H07-msc,
  title = "Complexity of Subsumption in Extensions of EL",
  author = "Christoph Haase",
  year = "2007",
  month = "August",
  school = "TU Dresden",
  url = "http://web.comlab.ox.ac.uk//files/638/Haase-Msc-2007.pdf",
}