O. Kutz, and T. Mossakowski. Proceedings of the Twenty-Fifth AAAI Conference on Artificial Intelligence and the Twenty-Third Innovative Applications of Artificial Intelligence Conference, page 227-234. AAAI Press; Menlo Park, CA, (2011)
E. Dashofy, A. van der Hoek, and R. Taylor. Proceedings of the 24rd International Conference on Software Engineering, 2002. ICSE 2002, page 266--276. IEEE, (May 2002)