@inproceedings {4970,
	title = {Conjunctive Query Answering in the Description Logic EL Using A Relational Database System},
	booktitle = {International Joint Conference on Artificial Intelligence (IJCAI)},
	year = {2009},
	url = {http://ijcai.org/Proceedings/09/Papers/341.pdf},
	author = {Carsten Lutz and David Toman and Frank Wolter}
}
