@inproceedings{PODS-2009-FaginKPT,
	author        = "Ronald Fagin and Phokion G. Kolaitis and Lucian Popa and Wang Chiew Tan",
	booktitle     = "{Proceedings of the 28th Symposium on Principles of Database Systems}",
	doi           = "10.1145/1559795.1559800",
	isbn          = "978-1-60558-553-6",
	pages         = "23--32",
	publisher     = "{ACM}",
	title         = "{Reverse data exchange: coping with nulls}",
	year          = 2009,
}