@inproceedings{SIGMOD-2011-CaoCJO,
	author        = "Xin Cao and Gao Cong and Christian S. Jensen and Beng Chin Ooi",
	booktitle     = "{Proceedings of the 29th ACM SIGMOD International Conference on Management of Data}",
	doi           = "10.1145/1989323.1989363",
	isbn          = "978-1-4503-0661-4",
	pages         = "373--384",
	publisher     = "{ACM}",
	title         = "{Collective spatial keyword querying}",
	year          = 2011,
}