Barrington, James (31 March 2006). "Switching Signals". Intertel. Transdiffusion Broadcasting System. Archived from the original on 22 June 2006. Retrieved 2 December 2006.
Barrington, James (31 March 2006). "Switching Signals". Intertel. Transdiffusion Broadcasting System. Archived from the original on 22 June 2006. Retrieved 2 December 2006.