F. Lehmann, and R. Wille. Conceptual Structures: Applications, Implementation and Theory, volume 954 of Lecture Notes in Computer Science, Springer, (1995)
P. Eklund, B. Groh, G. Stumme, and R. Wille. Conceptual Structures: Logical, Linguistic, and Computational, volume 1867 of LNAI, page 453-467. Heidelberg, Springer, (2000)
M. Skorsky, G. Stumme, R. Wille, and U. Wille. Proc. Workshop on Knowledge Management, Organizational Memory and Reuse, 5th German Conf. on, Würzburg, (March 1999)