1. GST: Global System for Telematics, http://www.gstforum.org/.
2. NOW: Network on Wheels, http://www.network-on-wheels.de/.
3. PReVENT, http://www.prevent-ip.org/.
4. Sevecom: Secure Vehicular Communication, http://www.sevecom.org/.
5. Cross-layer privacy enhancement and non-repudiation in vehicular communication;Armknecht,2007