@inproceedings{RE-1997-Rushby,
	author        = "John M. Rushby",
	booktitle     = "{Proceedings of the Third International Symposium on Requirements Engineering}",
	doi           = "10.1109/RE.1997.10005",
	isbn          = "0-8186-7740-6",
	pages         = "144--None",
	publisher     = "{IEEE Computer Society}",
	title         = "{Calculating with Requirements}",
	year          = 1997,
}