X. Zhang, N. Mamoulis, D. Cheung, and Y. Shou. Proceedings of the tenth ACM SIGKDD international conference on Knowledge discovery and data mining, page 384--393. ACM, (2004)
F. Giannotti, M. Nanni, F. Pinelli, and D. Pedreschi. Proceedings of the 13th ACM SIGKDD international conference on Knowledge discovery and data mining, page 330--339. ACM, (2007)