@inproceedings{SIGFIDET-1971-Codd,
	author        = "E. F. Codd",
	booktitle     = "{Proceedings of the Second ACM-SIGFIDET Workshop on Data Description, Access and Control}",
	cdrom         = "SIGFIDET71/P035.pdf",
	pages         = "35--68",
	publisher     = "{ACM}",
	title         = "{A Database Sublanguage Founded on the Relational Calculus}",
	year          = 1971,
}