@inproceedings{CADE-2007-LutzW,
	author        = "Carsten Lutz and Frank Wolter",
	booktitle     = "{Proceedings of the 21st International Conference on Automated Deduction}",
	doi           = "10.1007/978-3-540-73595-3_7",
	isbn          = "978-3-540-73594-6",
	pages         = "84--99",
	publisher     = "{Springer International Publishing}",
	series        = "{Lecture Notes in Computer Science}",
	title         = "{Conservative Extensions in the Lightweight Description Logic EL}",
	volume        = 4603,
	year          = 2007,
}