@article{VLDB-2015-KohlerLZ,
	author        = "Henning Köhler and Sebastian Link and Xiaofang Zhou",
	ee            = "http://www.vldb.org/pvldb/vol8/p1118-koehler.pdf",
	journal       = "{Proceedings of the VLDB Endowment}",
	number        = 11,
	pages         = "1118--1129",
	title         = "{Possible and Certain SQL Key}",
	volume        = 8,
	year          = 2015,
}