@inproceedings{SIGMOD-1988-AbiteboulH,
	author        = "Serge Abiteboul and Richard Hull",
	booktitle     = "{Proceedings of the 18th ACM SIGMOD International Conference on Management of Data}",
	cdrom         = "SIGMOD88/P143.PDF",
	doi           = "10.1145/50202.50218",
	pages         = "143--153",
	title         = "{Data Functions, Datalog and Negation}",
	year          = 1988,
}