Carlsson, Barbara (October 2002). "GLOBALink/VHF: The Future Is Now"(PDF). The Global Link (Press release). p. 4. Archived from the original(PDF) on 11 February 2006. Retrieved 24 January 2007.
Carlsson, Barbara (October 2002). "GLOBALink/VHF: The Future Is Now"(PDF). The Global Link (Press release). p. 4. Archived from the original(PDF) on 11 February 2006. Retrieved 24 January 2007.
Tooley, Michael H.; Wyatt, David (2007). Aircraft communications and navigation systems: Principles, operation and maintenance. Amsterdam: Elsevier/Butterworth-Heineman. ISBN978-0750681377. OCLC127107537.