@TechReport{HoSatTob-LTCS-99-08,
  author = 	 {I. Horrocks and U. Sattler and S. Tobies},
  title = 	 {A Description Logic with Transitive and Converse Roles, Role
Hierarchies and Qualifying Number Restrictions},
  institution =  {LuFG Theoretical Computer Science, RWTH Aachen},
  year = 	 1999,
 type           = {LTCS-Report},
  number =	 {LTCS-99-08},
  issuedate =    { February 2, 1999},
  note = {Revised version. See http://www-lti.informatik.rwth-aachen.de/Forschung/Reports.html},
  keywords = { Description Logic, Transitive Roles, Decision Procedure, Abox }
}