B. Demuth, and H. Liebau. Proceedings of the International Symposium on Advances in Rule Interchange and Applications (RuleML’07), volume 4824 of Lecture Notes in Computer Science, page 119-133. Berlin, Springer, (2007)
M. Hristozova, and L. Sterling. In Workshop on Ontologies in Agent Systems, 1st International Joint Conference on Autonomous Agents and Multi-Agent Systems, (2002)