S. Bergweiler, M. Deru, and D. Porta. ACM International Conference on Interactive Tabletops and Surfaces, page 245--246. New York, NY, USA, ACM, (2010)
A. Torralba, K. Murphy, W. Freeman, and M. Rubin. Computer Vision, 2003. Proceedings. Ninth IEEE International Conference
on, page 273--280 vol.1. (2003)
A. Komninos, and S. Stamou. Proceedings of UbiHealth 2006: The 4th International Workshop on
Ubiquitous Computing for Pervasive Healthcare Applications, (2006)