F. Beil, M. Ester, and X. Xu. Proceedings of the eighth ACM SIGKDD international conference on Knowledge discovery and data mining, page 436--442. ACM Press, (2002)
M. y Gómez, A. Gelbukh, and A. López-López. Proceedings of the 10th International Conference on Conceptual Structures (ICCS 2002), volume 2393 of Lecture Notes in Computer Science, page 122-136. Springer, (2002)
A. Hotho, S. Staab, and G. Stumme. Proceedings of the 2003 IEEE International Conference on Data Mining, page 541-544 (Poster. Melbourne, Florida, IEEE Computer Society, (November 2003)