@inproceedings {4966,
	title = {Combined FO Rewritability for Conjunctive Query Answering in DL-Lite},
	booktitle = {International Workshop on Description Logics (DL)},
	year = {2009},
	url = {http://ceur-ws.org/Vol-477/paper_32.pdf},
	author = {Roman Kontchakov and Carsten Lutz and David Toman and Frank Wolter and Michael Zakharyaschev}
}
