J. Broekstra, A. Kampman, und F. van Harmelen. The Semantic Web -- ISWC 2002: First International Semantic Web Conference Sardinia, Italy, Volume 2342 von Lecture Notes in Computer Science, Springer, Berlin, (2002)
P. Rangel, J. Carvalho Junior, M. Ramirez, und J. de Souza. Proceedings of the Sixth International Conference on Intelligent Environments (IE 2010), Kuala Lumpur, Malaysia, Seite 116--121. Los Alamitos, CA, IEEE Computer Society CPS, (2010)