@inproceedings{PODS-2004-GutierrezHM,
	author        = "Claudio Gutiérrez and Carlos A. Hurtado and Alberto O. Mendelzon",
	booktitle     = "{Proceedings of the 23rd Symposium on Principles of Database Systems}",
	doi           = "10.1145/1055558.1055573",
	ee            = "http://www.acm.org/sigmod/pods/proc04/pdf/P-10.pdf",
	isbn          = "1-58113-858-X",
	pages         = "95--106",
	publisher     = "{ACM}",
	title         = "{Foundations of Semantic Web Databases}",
	year          = 2004,
}