F. Geerts, B. Goethals, and T. Mielikäinen. Proceedings of the Second International Workshop on Inductive Databases, 22 September, Cavtat-Dubrovnik, Croatia, page 60-69. (2003)
B. Goethals, and J. den Bussche. Proceedings of the Second International Conference on Data Warehousing and Knowledge Discovery, volume 1874 of Lecture Notes in Computer Science, page 307--316. Springer-Verlag, (2000)
C. Garboni, and F. Masseglia. Proc. of the 6th International Workshop on Symbolic and Numeric Algorithms for Scientific Computing, SYNASC 2004, Timisoara, Romania, (26-30 September 2004)