S. Noël, and R. Beale. Proceedings of the 22nd British CHI Group Annual Conference on HCI 2008: People and Computers XXII: Culture, Creativity, Interaction, 2, page 71-74. (2008)
P. Heymann, G. Koutrika, and H. Garcia-Molina. WSDM '08: Proceedings of the international conference on Web search and web data mining, page 195--206. New York, NY, USA, ACM, (2008)
S. Bao, G. Xue, X. Wu, Y. Yu, B. Fei, and Z. Su. WWW '07: Proceedings of the 16th international conference on World Wide Web, page 501--510. New York, NY, USA, ACM, (2007)