B. Yu, and M. Singh. Cooperative Information Agents IV - The Future of Information Agents in Cyberspace, volume 1860 of Lecture Notes in Computer Science, Springer, Berlin/Heidelberg, (2000)
N. Dokoohaki, and M. Matskin. Advances in Intelligent Web Mastering - 2, volume 67 of Advances in Intelligent and Soft Computing, Springer, Berlin / Heidelberg, (2010)