Grahl, Miranda, Hotho, Andreas and Stumme, Gerd. "Conceptual Clustering of Social Bookmarking Sites." Paper presented at the meeting of the 7th International Conference on Knowledge Management (I-KNOW '07), Graz, Austria, 2007.

Santos-Neto, Elizeu, Ripeanu, Matei and Iamnitchi, Adriana Tracking User Attention in Collaborative Tagging Communities. (2007). .

Begelman, G., Keller, P. and Smadja, F.. "Automated Tag Clustering: Improving search and exploration in the tag space." WWW2006, May (2006): 22--26.

Heymann, Paul and Garcia-Molina, Hector Collaborative Creation of Communal Hierarchical Taxonomies in Social Tagging Systems. (2006-10) , Computer Science Department (2006). .

Mika, Peter. "Ontologies Are Us: A Unified Model of Social Networks and Semantics." Paper presented at the meeting of the International Semantic Web Conference, 2005.