Mika, Peter. Ontologies Are Us: A Unified Model of Social Networks and Semantics. International Semantic Web Conference. LNCS, 522-536, Springer, Year 2005.
Schmitz, Christoph and Hotho, Andreas and Jäschke, Robert and Stumme, Gerd. Mining Association Rules in Folksonomies. Data Science and Classification (Proc. IFCS 2006 Conference). editor(s) Batagelj, V. and Bock, H.-H. and Ferligoj, A. and Žiberna, A.. Studies in Classification, Data Analysis, and Knowledge Organization, 261-270, Springer, Berlin/Heidelberg, Year 2006.
Heylighen, Francis. Bootstrapping knowledge representations: from entailment meshes via semantic nets to learning webs. In Kybernetes, (30) 5/6: 691--722, Year 2001.