@BOOK {
	EDITOR = "Pablo Barcel{\'o} and Reinhard Pichler",
	TITLE = "Proceedings of the 2nd International Workshop on Datalog (Datalog)",
	MONTH = "Sep",
	YEAR = "2012",
	ADDRESS = "Vienna, Austria",
	PUBLISHER = "Springer-Verlag",
	SERIES ="LNCS",
	}