@inproceedings{CAiSE-1997-WieringaDH,
	author        = "Roel Wieringa and Eric Dubois and Sander Huyts",
	booktitle     = "{Proceedings of the Ninth International Conference on Advanced Information Systems Engineering}",
	doi           = "10.1007/3-540-63107-0_2",
	isbn          = "3-540-63107-0",
	pages         = "19--32",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Integrating Semi-formal and Formal Requirements}",
	volume        = 1250,
	year          = 1997,
}