@inproceedings {4958,
	title = {The Combined Approach to OBDA: Taming Role Hierarchies Using Filters},
	booktitle = {International Semantic Web Conference (ISWC)},
	year = {2012},
	url = {http://ceur-ws.org/Vol-943/SSWS_HPCSW2012_paper2.pdf},
	author = {Carsten Lutz and Inan{\c c} Seylan and David Toman and Frank Wolter}
}
