M. Krötzsch, D. Vrandecic, и M. Völkel. The Semantic Web - ISWC 2006, 5th International Semantic Web Conference, ISWC 2006, Athens, GA, USA, November 5-9, 2006, Proceedings, том 4273 из Lecture Notes in Computer Science, стр. 935--942. Springer, (2006)