S. Izadi, H. Brignull, T. Rodden, Y. Rogers, and M. Underwood. UIST '03: Proceedings of the 16th annual ACM symposium on User interface software and technology, page 159--168. New York, NY, USA, ACM Press, (2003)
S. Izadi, T. Härder, and M. Haghjoo. Grundlagen von Datenbanken, volume 01/2008 of Technical Report, page 76-80. School of Information Technology, International University in Germany, (2008)