X. Yang, L. Liu, N. Vaidya, and F. Zhao. The First Annual International Conference on Mobile and Ubiquitous
Systems: Networking and Services (MOBIQUITOUS), page 114 - 123. (August 2004)
S. Weber, Y. Kalev, S. Ries, and M. Mühlhäuser. Proceedings of the 5th International Conference on Ubiquitous Information Management and Communication, page 29:1--29:10. New York, NY, USA, ACM, (2011)