@inproceedings{KR-1989-Hirst,
	author        = "Graeme Hirst",
	booktitle     = "{Proceedings of the First International Conference on Principles of Knowledge Representation and Reasoning}",
	isbn          = "1-55860-032-9",
	pages         = "157--169",
	publisher     = "{Morgan Kaufmann}",
	title         = "{Ontological Assumptions in Knowledge Representation}",
	year          = 1989,
}