T. Butter, M. Aleksy, P. Bostan, and M. Schader. Proceedings of the 27th International Conference on Distributed Computing Systems - Workshops (ICDCS Workshops 2007), Toronto, Ontario, Canada, (2007)
T. Butter, I. Duda, M. Aleksy, and M. Schader. Proceedings of the IADIS International Conference e-Commerce 2006, page 308--312. Barcelona, Spain, (2006)