E. Mohyeldin, M. Fahrmair, W. Sitou, and B. Spanfelner. The 16th Annual IEEE International Symposium on Personal Indoor and Mobile Radio Communications (PIMRC05), 11-14 September 2005, Berlin, Germany, (2005)
S. Pietschmann, V. Tietz, J. Reimann, C. Liebing, M. Pohle, and K. Meißner. Proceedings of the 12th International Conference on Information Integration and Web-based Applications &\#38; Services, page 413--420. New York, NY, USA, ACM, (2010)