Alessandro Artale Roman Kontchakov Vladislav Ryzhikov Michael Zakharyaschev <i>DL-Lite</i> with Temporalised Concepts, Rigid Axioms and Roles. 133-148 2009 FroCos http://dx.doi.org/10.1007/978-3-642-04222-5_8 conf/frocos/2009 db/conf/frocos/frocos2009.html#ArtaleKRZ09