@inproceedings{TOOLS-USA-1991-Duke,
	author        = "Roger Duke",
	booktitle     = "{Proceedings of the Fifth International Conference on Technology of Object-Oriented Languages and Systems}",
	isbn          = "0-13-923178-1",
	pages         = "463--464",
	publisher     = "{Prentice Hall}",
	title         = "{Formal Specification of Object-Oriented Systems}",
	year          = 1991,
}