Sen, S.; Lam, S. K.; Rashid, A. M.; Cosley, D.; Frankowski, D.; Osterhouse, J.; Harper, F. M. & Riedl, J. (2006), tagging, communities, vocabulary, evolution, in 'CSCW '06: Proceedings of the 2006 20th anniversary conference on Computer supported cooperative work' , ACM, New York, NY, USA , pp. 181--190 .