@inproceedings{KR-1991-Schaub,
	author        = "Torsten Schaub",
	booktitle     = "{Proceedings of the Second International Conference on Principles of Knowledge Representation and Reasoning}",
	isbn          = "1-55860-165-1",
	pages         = "496--506",
	publisher     = "{Morgan Kaufmann}",
	title         = "{Assertional Default Theories: A Semantical View}",
	year          = 1991,
}