M. Keeler. Proceedings of the 18th International Conference on Conceptual Structures (ICCS 2010), volume 6208 of Lecture Notes in Computer Science, page 108-124. Springer, (2010)
F. Southey, and J. Linders. Proceedings of the 9th International Conference on Conceptual Structures (ICCS 2001), volume 2120 of Lecture Notes in Computer Science, page 333-345. Springer, (2001)
A. de Moor, and W. van den Heuvel. Proceedings of the 9th International Conference on Conceptual Structures (ICCS 2001), volume 2120 of Lecture Notes in Computer Science, page 260-274. Springer, (2001)