B. Yu, und M. Singh. Cooperative Information Agents IV - The Future of Information Agents in Cyberspace, Volume 1860 von Lecture Notes in Computer Science, Springer, Berlin/Heidelberg, (2000)
M. Rosen-Zvi, T. Griffiths, M. Steyvers, und P. Smyth. Proceedings of the 20th conference on Uncertainty in artificial intelligence, Seite 487--494. Arlington, VA, USA, AUAI Press, (2004)