@inproceedings{PODS-1987-Ullman,
	author        = "Jeffrey D. Ullman",
	booktitle     = "{Proceedings of the Sixth Symposium on Principles of Database Systems}",
	cdrom         = "['journals/anthology/cd1-3:PODS87/P001.PDF', 'journals/anthology/dvd1:text/1-3/PODS87/P001.PDF']",
	doi           = "10.1145/28659.28660",
	isbn          = "0-89791-223-3",
	pages         = "1--10",
	publisher     = "{ACM}",
	title         = "{Database Theory: Past and Future}",
	year          = 1987,
}