W. Lam, S. Mukhopadhyay, J. Mostafa, and M. Palakal. 19th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, page 317-325. Zurich, Switzerland, (1996)
I. Ferguson, and G. Karakoulas. Working qNotes for the AAAI Symposium on Adaptation, Co-evolution and Learning in Multiagent Systems., Stanford Univeristy, California, (1996)