A. Yahia, L. Lakhal, J. Bordat, and R. Cicchetti. Proc. 15th Intl. Conf. on Conceptual Modeling, volume 1157 of LNCS, page 422--437. Springer, Heidelberg, (1996)
Y. Yao. Proceedings of 2004 Annual Meeting of the North American Fuzzy Information Processing Society(NAFIPS 2004),IEEE Catalog Number: 04 TH 8736, page 796-801. (2004)
Y. Yao, and J. Mi. RSKT '09: Proceedings of the 4th International Conference on Rough Sets and Knowledge Technology, page 601--609. Berlin, Heidelberg, Springer-Verlag, (2009)
M. Yuan, W. Li, and L. Zhangang. WCSE '09: Proceedings of the 2009 WRI World Congress on Software Engineering, page 94--98. Washington, DC, USA, IEEE Computer Society, (2009)
M. Zaki, S. Parthasarathy, M. Ogihara, and W. Li. Proceedings of the 3rd international conference on Knowledge Discovery
and Data mining (KDD'97), page 283--286. AAAI Press, (August 1997)
O. Zaïane, J. Han, Z. Li, S. Chee, and J. Chiang. Proceedings of the 1998 ACM SIGMOD international conference on Management
of Data (SIGMOD'98), page 581--583. ACM Press, (June 1998)