Yasushi Kiyoki Takahiro Tokuda Hannu Jaakkola Xin Chen Naofumi Yoshida Information Modelling and Knowledge Bases XX, 18th European-Japanese Conference on Information Modelling and Knowledge Bases (EJC 2008), Tsukuba, Japan, June 2-6, 2008 EJC Frontiers in Artificial Intelligence and Applications 190 IOS Press 2009 978-1-58603-957-8 db/conf/ejc/ejc2008.html