C. Brooks, and N. Montanez. WWW ’06: Proceedings of the 15th international conference on World Wide Web, page 625--632. New York, NY, USA, ACM Press, (2006)
Y. Hassan-Montero, and V. Herrero-Solana. International Conference on Multidisciplinary Information Sciences and Technologies, InSci2006, (25-28 aug 2006)