H. Nakashima, I. Noda, and I. Ohsawa. ICMAS-95 Proceedings First International Conference on
Multi-Agent Systems, page 459. San Francisco, California, USA, AAAI Press/MIT Press, (12--14 June 1995)
A. Ito, and H. Yano. ICMAS-95 Proceedings First International Conference on
Multi-Agent Systems, page 201--208. San Francisco, California, USA, AAAI Press/MIT Press, (12--14 June 1995)