A. Drummond, T. Bachman, and J. Antaki. International Conference on Computational Science (4), volume 3994 of Lecture Notes in Computer Science, page 855-861. Springer, (2006)
C. Drummond, and R. Holte. Proceedings of the Seventeenth International Conference on Machine Learning, page 239--246. San Francisco, CA, USA, Morgan Kaufmann Publishers Inc., (2000)