B. Burnell, R. Bitmead, and A. Connolly. Proceedings of the 41st IEEE Conference on Decision and Control, 4, page 4649 - 4651. The Venetian Hotel, Las Vegas, Nevada, USA, IEEE, (10-13 12 2002)
B. Carterette, J. Allan, and R. Sitaraman. SIGIR '06: Proceedings of the 29th annual international ACM SIGIR conference on Research and development in information retrieval, page 268--275. New York, NY, USA, ACM, (2006)