B. Guo, S. Satake, and M. Imai. IAT '06: Proceedings of the IEEE/WIC/ACM International Conference on Intelligent Agent Technology, Hong Kong, page 191-194. Washington, DC, USA, IEEE Computer Society, (2006)
G. Herzog, and K. Rohr. KI-95: Advances in Artificial Intelligence, 19th Annual German Conference on Artificial Intelligence, Bielefeld, Germany, volume 981 of Lecture Notes in Artificial Intelligence, Springer, Berlin, (1995)