A. Mislove, B. Viswanath, K. Gummadi, and P. Druschel. Proceedings of the Third ACM International Conference on Web Search and Data Mining, page 251--260. New York, NY, USA, ACM, (2010)
S. Wu, J. Hofman, W. Mason, and D. Watts. Proceedings of the 20th International Conference on World Wide Web, page 705--714. New York, NY, USA, ACM, (2011)
S. Rudolph. Proceedings of the 15th International Conference on Conceptual Structures (ICCS 2007), volume 4604 of Lecture Notes in Artificial Intelligence, page 321-332. Berlin, Heidelberg, Springer-Verlag, (July 2007)