D. Carmel, E. Yom-Tov, A. Darlow, und D. Pelleg. SIGIR '06: Proceedings of the 29th annual international ACM SIGIR conference on Research and development in information retrieval, Seite 390--397. New York, NY, USA, ACM, (2006)
C. McNaught, K. Whithear, und G. Browning. Interactive Multimedia in University Education, Volume A-59 von IFIP Transactions, Seite 295-307. Elsevier, (1994)