@inproceedings{PODS-2012-FaginK,
	author        = "Ronald Fagin and Phokion G. Kolaitis",
	booktitle     = "{Proceedings of the 31st Symposium on Principles of Database Systems}",
	doi           = "10.1145/2213556.2213583",
	isbn          = "978-1-4503-1248-6",
	pages         = "179--190",
	publisher     = "{ACM}",
	title         = "{Local transformations and conjunctive-query equivalence}",
	year          = 2012,
}