S. Auer, C. Bizer, G. Kobilarov, J. Lehmann, R. Cyganiak, and Z. Ives. Proceedings of the 6th International Semantic Web Conference (ISWC), volume 4825 of Lecture Notes in Computer Science, page 722--735. Springer, (2008)
Y. Yang, and J. Calmet. Computational Intelligence for Modelling, Control and Automation, 2006 and International Conference on Intelligent Agents, Web Technologies and Internet Commerce, International Conference on, page 127-127. (2006)