X. Wu, L. Zhang, and Y. Yu. WWW '06: Proceedings of the 15th international conference on World Wide Web, page 417-426. New York, NY, USA, ACM Press, (2006)
A. Hotho, R. Jäschke, C. Schmitz, and G. Stumme. Proceedings of the First Conceptual Structures Tool Interoperability Workshop at the 14th International Conference on Conceptual Structures, page 87-102. Aalborg, Aalborg Universitetsforlag, (2006)