U. Fayyad, G. Piatetsky-Shapiro, and P. Smyth. Advances in knowledge discovery and data mining, American Association for Artificial Intelligence, Menlo Park, CA, USA, (1996)
T. Zhang, R. Ramakrishnan, and M. Livny. Proceedings of the 1996 ACM SIGMOD International Conference on Management of Data, page 103--114. New York, NY, USA, ACM, (1996)
J. Hereth, G. Stumme, R. Wille, and U. Wille. Conceptual Structures: Logical, Linguistic, and Computational Issues. Proc. ICCS '00, volume 1867 of LNAI, page 421-437. Heidelberg, Springer, (2000)