How opinions are received by online communities: A case study on Amazon.com helpfulness votes, Cristian Danescu-Niculescu-Mizil, Gueorgi Kossinets, Jon Kleinberg, Lillian Lee, Proceedings of the 18th International Conference on World Wide Web, WWW 2009, Madrid, Spain, April 20-24, 2009, pp. 141-150.
Origins of Homophily in an Evolving Social Network, Gueorgi Kossinets, Duncan J. Watts, American Journal of Sociology, vol. 115 (2009), pp. 405-450.