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2. Third Generation Partnership Project (3GPP). Security aspects of early IP Multimedia Subsystem (IMS) (Release 8).TR 33.178 V1.0.0, 2008.
3. European Telecommunications Standards Institute (ETSI). Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); NGN Security; Security Architecture. TS 187 003, 2006.
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