Inproceedings (grahl2007clustering)
Grahl, M.; Hotho, A. & Stumme, G.
Conceptual Clustering of Social Bookmarking Sites
Know-Center, 2007, 356-364

Misc (santosneto-2007)
Santos-Neto, E.; Ripeanu, M. & Iamnitchi, A.
Tracking User Attention in Collaborative Tagging Communities
2007

2006

Article (begelman2006atc)
Begelman, G.; Keller, P. & Smadja, F.
Automated Tag Clustering: Improving search and exploration in the tag space
WWW2006, May, 2006, 22-26

Techreport (citeulike:739394)
Heymann, P. & Garcia-Molina, H.
Collaborative Creation of Communal Hierarchical Taxonomies in Social Tagging Systems
Standford University, Computer Science Department, 2006

2005

Inproceedings (Mika2005)
Mika, P.
Ontologies Are Us: A Unified Model of Social Networks and Semantics
Springer, 2005, 522-536