1. CEN: European Committee for Standardization.
http://www.cen.eu/
. Accessed 15 Oct 2016
2. ISO: International Organization for Standardization.
http://www.iso.org/
. Accessed 15 Oct 2016
3. ITU: International Telecommunication Union.
https://www.itu.int
. Accessed 15 Oct 2016
4. IEEE: Institute of Electrical and Electronics Engineers IEEE.
https://www.ieee.org/index.html
. Accessed 12 Oct 2017
5. IETF: Internet Engineering Task Force.
https://www.ietf.org/
. Accessed 15 Oct 2016