@INPROCEEDINGS {
	AUTHOR = "Pablo Barcel{\'o} and Leonid Libkin and Miguel Romero",
	TITLE = "Efficient Approximations of Conjunctive Queries",
	BOOKTITLE = "31st ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Database Systems (PODS)",
	PAGES = "249-260",
	MONTH = "May",
	YEAR = "2012",
	ADDRESS = "Scottsdale, AZ, USA",
	PUBLISHER = "ACM Press",
	SERIES ="ACM International Conference Proceeding Series",
	}