@inproceedings{PODS-2006-Libkin,
	author        = "Leonid Libkin",
	booktitle     = "{Proceedings of the 25th Symposium on Principles of Database Systems}",
	doi           = "10.1145/1142351.1142360",
	isbn          = "1-59593-318-2",
	pages         = "60--69",
	publisher     = "{ACM}",
	title         = "{Data exchange and incomplete information}",
	year          = 2006,
}