@inproceedings{ICALP-1991-FixFG,
	author        = "Limor Fix and Nissim Francez and Orna Grumberg",
	booktitle     = "{Proceedings of the 18th International Colloquium on Automata, Languages and Programming}",
	doi           = "10.1007/3-540-54233-7_127",
	isbn          = "3-540-54233-7",
	pages         = "93--114",
	publisher     = "{Springer-Verlag}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Program Composition and Modular Verification}",
	volume        = 510,
	year          = 1991,
}