E. Bakshy, J. Hofman, W. Mason, and D. Watts. Proceedings of the Fourth ACM International Conference on Web Search and Data Mining, page 65--74. New York, NY, USA, ACM, (2011)
P. Desikan, N. Pathak, J. Srivastava, and V. Kumar. ICWE '06: Proceedings of the 6th international conference on Web engineering, page 233--240. New York, NY, USA, ACM Press, (July 2006)