Ming-Che Lee Kun Hua Tsai Tung Cheng Hsieh Ti Kai Chiu Tzone I. Wang An Ontological Approach for Semantic Learning Objects Interoperability. 222-226 2007 conf/icalt/2007 ICALT http://doi.ieeecomputersociety.org/10.1109/ICALT.2007.63 db/conf/icalt/icalt2007.html#LeeTHCW07