Terukazu Kumazawa Osamu Saito Kouji Kozaki Takanori Matsui Riichiro Mizoguchi Knowledge Structuring Tool for Sustainability Science Based on Ontology Engineering. 1138-1143 2009 CISIS http://doi.ieeecomputersociety.org/10.1109/CISIS.2009.172 conf/cisis/2009 db/conf/cisis/cisis2009.html#KumazawaSKMM09