Sok-Ian Sou, Quincy Wu, Yi-Bing Lin, Che-Hua Yeh. Prepaid mechanism of VoIP and messaging services. In ITRE 2005 - 3rd International Conference on Information Technology: Research and Education, June 27-30 2005, Hsinchu, Taiwan, Proceedings. pages 255-259, IEEE, 2005. [doi]
Abstract is missing.