1. W.P. Lee, C.H. Liu and C.C. Lu: Journal of Expert Systems with Applications, Vol. 22 (2002), p.275.
2. B. Archimede and T. Coudert: Journal of Application Artificial Intelligence, Vol. 14 (2001), p.669.
3. K. Kurbel and I. Loutchko: Journal of Electronic Commerce Research and Applications, Vol. 4, (2005), p.188.
4. Y.M. Chen and S.C. Wang: Journal of Application Soft Computer, Vol. 7 (2007), p.236.
5. S. Kraus, J. Wilkenfeld and G. Zlotkin: Journal of Application Artificial Intelligence, Vol. 75 (1995), p.320.