@inproceedings{KR-1994-Teege,
	author        = "Gunnar Teege",
	booktitle     = "{Proceedings of the Fourth International Conference on Principles of Knowledge Representation and Reasoning}",
	isbn          = "1-55860-328-X",
	pages         = "540--550",
	publisher     = "{Morgan Kaufmann}",
	title         = "{Making the Difference: A Subtraction Operation for Description Logics}",
	year          = 1994,
}