S. Rudolph, M. Krötzsch, и P. Hitzler. Proceedings of the 15th International Conference on Conceptual Structures (ICCS 2007), том 4604 из Lecture Notes in Artificial Intelligence, стр. 464-467. Berlin, Heidelberg, Springer-Verlag, (июля 2007)
S. Rudolph. Proceedings of the 12th International Conference on Conceptual Structures (ICCS 2004), том 3127 из Lecture Notes in Computer Science, стр. 196-212. Springer, (2004)