@inproceedings{VLDB-1991-ArefS,
	author        = "Walid G. Aref and Hanan Samet",
	booktitle     = "{Proceedings of the 17th International Conference on Very Large Data Bases}",
	ee            = "http://www.vldb.org/conf/1991/P081.PDF",
	isbn          = "1-55860-150-3",
	pages         = "81--90",
	publisher     = "{Morgan Kaufmann}",
	title         = "{Optimization for Spatial Query Processing}",
	year          = 1991,
}