@inproceedings{KR-1991-GelfondPLT,
	author        = "Michael Gelfond and Halina Przymusinska and Vladimir Lifschitz and Miroslaw Truszczynski",
	booktitle     = "{Proceedings of the Second International Conference on Principles of Knowledge Representation and Reasoning}",
	isbn          = "1-55860-165-1",
	pages         = "230--237",
	publisher     = "{Morgan Kaufmann}",
	title         = "{Disjective Defaults}",
	year          = 1991,
}