A. Hotho, R. Jäschke, C. Schmitz, and G. Stumme. Proceedings of the Conceptual Structure Tool Interoperability Workshop at the 14th International Conference on Conceptual Structures, page 87-102. (2006)
B. Krause, A. Hotho, and G. Stumme. Advances in Information Retrieval, 30th European Conference on IR Research, ECIR 2008, 4956, page 101-113. Springer, (2008)