R. Klamma, and C. Haasler. Proceedings of I-KNOW '08 and I-MEDIA '08, page 276--279. Know-Center, Graz, Journal of Universal Computer Science, (September 2008)
F. Ortega, J. Gonzalez-Barahona, and G. Robles. HICSS '08: Proceedings of the Proceedings of the 41st Annual Hawaii International Conference on System Sciences, page 304. Washington, DC, USA, IEEE Computer Society, (2008)
H. Halpin, V. Robu, and H. Shepherd. WWW '07: Proceedings of the 16th international conference on World Wide Web, page 211--220. New York, NY, USA, ACM, (2007)