C. Decker, T. Riedel, M. Beigl, L. de Souza, P. Spiess, J. Müller, и S. Haller. Proceedings of the 3rd IET International Conference on Intelligent Environments (IE 07), Ulm, Germany, стр. 40--47. Institution of Engineering and Technology (IET), London, (2007)
C. Drumm, J. Lemcke, и D. Oberle. The Semantic Web: Real-World Applications from Industry, том 6 из Semantic Web and Beyond, Springer, New York, (2008)