A. Frieder, R. Lin, and S. Kraus. Proceedings of the 11th International Conference on Autonomous Agents and Multiagent Systems - Volume 3, page 1281–1282. Richland, SC, International Foundation for Autonomous Agents and Multiagent Systems, (2012)
Y. Li, A. Wen, Q. Lin, R. Li, and Z. Lu. Web-Age Information Management, volume 6897 of Lecture Notes in Computer Science, Springer, Berlin/Heidelberg, (2011)