@ARTICLE {
	AUTHOR = "Marcelo Arenas and Pablo Barcel{\'o} and Juan Reutter",
	TITLE ="Query Languages for Data Exchange: Beyond Unions of Conjunctive Queries",
	JOURNAL = "Theory of Computing Systems (ToCS)",
	VOLUME = "49",
	NUMBER = "4",
	PAGES = "489-564",
	MONTH = "Jul",
	YEAR = "2011",
	PUBLISHER = "Springer-Verlag",
	ADDRESS = "Berlin/Heidelberg, Germany",
	ISSN ="1433-0490",
	}