A. de Moor, P. Leenheer, and R. Meersman. Proceedings of the 14th International Conference on Conceptual Structures (ICCS 2006), volume 4068 of Lecture Notes in Computer Science, page 189-202. Springer, (2006)
A. de Moor, P. Leenheer, and R. Meersman. Proc. of the 14th International Conference on Conceptual Structures, (ICCS 2006), Aalborg, Denmark, Springer-Verlag, (2006)