@inproceedings{VDME-1991-HeeSV,
	author        = "Kees M. van Hee and Lou J. Somers and Marc Voorhoeve",
	booktitle     = "{Proceedings of the Fourth International Symposium on Vienna Development Method: Formal Software Development. Volume 1: Conference Contributions}",
	doi           = "10.1007/3-540-54834-3_14",
	isbn          = "3-540-54834-3",
	pages         = "204--219",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Z and High Level Petri Nets}",
	volume        = 551,
	year          = 1991,
}