D. Sonntag, and M. Möller. Proceedings of IUI '10: 15th International Conference on Intelligent User Interfaces, Hong Kong, China, page 381-384. (2010)
D. Sonntag, and M. Möller. Proceedings of the Sixth International Conference on Intelligent Environments (IE 2010), Kuala Lumpur, Malaysia, page 84--89. Los Alamitos, CA, IEEE Computer Society CPS, (2010)