@inproceedings{SIGMOD-1984-Willard,
	author        = "Dan E. Willard",
	booktitle     = "{Proceedings of the 14th ACM SIGMOD International Conference on Management of Data}",
	cdrom         = "SIGMOD84/P164.PDF",
	doi           = "10.1145/602259.602281",
	pages         = "164--175",
	publisher     = "{ACM Press}",
	title         = "{Efficient Processing of Relational Calculus Expressions Using Range Query Theory}",
	year          = 1984,
}