@inproceedings{POPL-1982-Cooper,
	author        = "Eric C. Cooper",
	booktitle     = "{Conference Record of the Ninth Annual Symposium on Principles of Programming Languages}",
	cdrom         = "['POPL/00001561.PDF', 'POPLs1/POPL1982/P361.PDF']",
	doi           = "10.1145/582153.582190",
	editor        = "Richard A. DeMillo",
	isbn          = "0-89791-065-6",
	pages         = "361--365",
	publisher     = "{ACM Press}",
	title         = "{On the Expressive Power of Query Languages for Relational Databases}",
	year          = 1982,
}