@ARTICLE {
	AUTHOR = "Pablo Barcel{\'o} and Leonid Libkin and Miguel Romero",
	TITLE ="Efficient Approximations of Conjunctive Queries",
	JOURNAL = "SIAM Journal on Computing (SICOMP)",
	VOLUME = "43",
	NUMBER = "3",
	PAGES = "1085-1130",
	YEAR = "2014",
	PUBLISHER = "SIAM Press",
	ADDRESS = "Philadelphia, USA",
	ISSN = "0097-5397"
	}