K. Wolff, und W. Yameogo. Proceedings of the 11th International Conference on Conceptual Structures (ICCS 2003), Volume 2746 von Lecture Notes in Computer Science, Seite 188-200. Springer, (2003)
H. Schärfe, und P. Øhrstrøm. Proceedings of the 11th International Conference on Conceptual Structures (ICCS 2003), Volume 2746 von Lecture Notes in Computer Science, Seite 201-214. Springer, (2003)