V. Shekhovtsov, H. Mayr, and C. Kop. CAiSE Forum (Selected Extended Papers), volume 204 of Lecture Notes in Business Information Processing, page 116-132. Springer, (2014)
H. de Swart, A. van Deemen, E. van der Hout, and P. Kop. Theory and Applications of Relational Structures as Knowledge Instruments, volume 2929 of Lecture Notes in Computer Science, Springer, (2003)