@inproceedings{PODS-2012-KostylevRS,
	author        = "Egor V. Kostylev and Juan L. Reutter and András Z. Salamon",
	booktitle     = "{Proceedings of the 31st Symposium on Principles of Database Systems}",
	doi           = "10.1145/2213556.2213590",
	isbn          = "978-1-4503-1248-6",
	pages         = "237--248",
	publisher     = "{ACM}",
	title         = "{Classification of annotation semirings over query containment}",
	year          = 2012,
}