@inproceedings{SIGMOD-1988-Vardi,
	author        = "Moshe Y. Vardi",
	booktitle     = "{Proceedings of the 18th ACM SIGMOD International Conference on Management of Data}",
	cdrom         = "SIGMOD88/P007.PDF",
	pages         = "7",
	title         = "{Database Logic Programming, Deductive Databases, and Expert Database Systems}",
	year          = 1988,
}