F. Solms, C. Edwards, A. Paar, and S. Gruner. Proceedings of the South African Institute of Computer Scientists and Information Technologists Conference on Knowledge, Innovation and Leadership in a Diverse, Multidisciplinary Environment, page 224--230. New York, NY, USA, ACM, (2011)
C. Pavlovski, and J. Zou. Proceedings of the fifth Asia-Pacific conference on Conceptual Modelling - Volume 79, page 103--112. Darlinghurst, Australia, Australia, Australian Computer Society, Inc., (2008)