M. Popovici, M. Muraru, A. Agache, C. Giumale, L. Negreanu, and C. Dobre. Proceedings of the 19th International Conference on Conceptual Structures (ICCS 2011), volume 6828 of Lecture Notes in Computer Science, page 215-228. Springer, (2011)
P. Pinheiro da Silva. Interactive Systems Design, Specification, and Verification, volume 1946 of Lecture Notes in Computer Science, Springer, Berlin / Heidelberg, (2001)