Joao Girão, João Paulo Barraca, Bernd Lamparter, Dirk Westhoff, Rui L. Aguiar. QoS-Differentiated Secure Charging in Ad-Hoc Environments. In José Neuman de Souza, Petre Dini, Pascal Lorenz, editors, Telecommunications and Networking - ICT 2004, 11th International Conference on Telecommunications, Fortaleza, Brazil, August 1-6, 2004, Proceedings. Volume 3124 of Lecture Notes in Computer Science, pages 1093-1100, Springer, 2004. [doi]