@article{VLDB-2012-BaranyCO,
	author        = "Vince Bárány and Balder ten Cate and Martin Otto",
	ee            = "http://vldb.org/pvldb/vol5/p1328_vincebarany_vldb2012.pdf",
	journal       = "{Proceedings of the VLDB Endowment}",
	number        = 11,
	pages         = "1328--1339",
	title         = "{Queries with Guarded Negation}",
	volume        = 5,
	year          = 2012,
}