Anbu Yue Weiru Liu Anthony Hunter Approaches to Constructing a Stratified Merged Knowledge Base. 54-65 2007 conf/ecsqaru/2007 ECSQARU http://dx.doi.org/10.1007/978-3-540-75256-1_8 db/conf/ecsqaru/ecsqaru2007.html#YueLH07