@inproceedings{PODS-2008-AfratiK,
	author        = "Foto N. Afrati and Phokion G. Kolaitis",
	booktitle     = "{Proceedings of the 27th Symposium on Principles of Database Systems}",
	doi           = "10.1145/1376916.1376936",
	isbn          = "978-1-60558-108-8",
	pages         = "129--138",
	publisher     = "{ACM}",
	title         = "{Answering aggregate queries in data exchange}",
	year          = 2008,
}