M. Croitoru, und R. Thomopoulos. Proceedings of the 17th International Conference on Conceptual Structures (ICCS 2009), Volume 5662 von Lecture Notes in Computer Science, Seite 128-140. Springer, (2009)
C. Laudy, B. Habib, und J. Ganascia. Proceedings of the 17th International Conference on Conceptual Structures (ICCS 2009), Volume 5662 von Lecture Notes in Computer Science, Seite 219-232. Springer, (2009)