@TechReport{BaSat97,
  author = 	 {Baader, F. and Sattler, U.},
  title = 	 {Description Logics with Aggregates and Concrete Domains},
  institution =  {LuFg Theoretical Computer Science, RWTH Aachen, Germany},
  year = 	 1997,
  number =	 {LTCS-97-01},
  type = {LTCS-Report},
  note = {An abridged version has appeared in the Proceedings of the
                  International Workshop on Description Logics 97.}
}