@article{Baader-JLC-96,
	author     = {F. Baader},
	title      = {A Formal Definition for the Expressive Power of 
                      Terminological Knowledge Representation Languages},
	journal    = {J. of Logic and Computation},
        volume     = {6},
	number     = {1},
	pages      = {33--54},
	freecopy = {yes},
 	year       = {1996}}