@inproceedings{SIGMOD-2009-GaoZ,
	author        = "Yunjun Gao and Baihua Zheng",
	booktitle     = "{Proceedings of the 27th ACM SIGMOD International Conference on Management of Data}",
	doi           = "10.1145/1559845.1559906",
	isbn          = "978-1-60558-551-2",
	pages         = "577--590",
	publisher     = "{ACM}",
	title         = "{Continuous obstructed nearest neighbor queries in spatial databases}",
	year          = 2009,
}