@inproceedings{PODS-1982-ChandraH,
	author        = "Ashok K. Chandra and David Harel",
	booktitle     = "{Proceedings of the First Symposium on Principles of Database Systems}",
	cdrom         = "['journals/anthology/cd1-3:PODS82/P158.PDF', 'journals/anthology/dvd1:text/1-3/PODS82/P158.PDF']",
	doi           = "10.1145/588111.588137",
	isbn          = "0-89791-070-2",
	pages         = "158--163",
	publisher     = "{ACM}",
	title         = "{Horn Clauses and the Fixpoint Query Hierarchy}",
	year          = 1982,
}