@TECHREPORT{BaaderSattler-LTCS-96-02,
 author         = {F. Baader and U. Sattler},
 title          = {Number Restrictions on Complex Roles in Description Logics}, 
 institution    = {LuFg Theoretical Computer Science, RWTH Aachen},
 year           = 1996,
 number         = {LTCS-96-02},
 note           = {An abridged version has appeared in the Proceedings of the
                  Fifth International Conference on Knowledge Representation and
                  Reasoning, 1996, Cambridge, Massachusetts.} 
}