@inproceedings{POPL-1980-Parikh,
	author        = "Rohit Parikh",
	booktitle     = "{Conference Record of the Seventh Annual Symposium on Principles of Programming Languages}",
	doi           = "10.1145/567446.567464",
	editor        = "Paul W. Abrahams and Richard J. Lipton and Stephen R. Bourne",
	isbn          = "0-89791-011-7",
	pages         = "186--192",
	publisher     = "{ACM Press}",
	title         = "{Propositional Logics of Programs: Systems, Models, and Complexity}",
	year          = 1980,
}