M. Keeler. Proceedings of the 15th International Conference on Conceptual Structures (ICCS 2007), том 4604 из Lecture Notes in Artificial Intelligence, стр. 443-459. Berlin, Heidelberg, Springer-Verlag, (июля 2007)
M. Keeler, и H. Pfeiffer. Proceedings of the 13th International Conference on Conceptual Structures (ICCS 2005), том 3596 из Lecture Notes in Computer Science, стр. 396-410. Springer, (2005)