Principles And Basic Technique For Good, Rhythmic Sending 0f Morse Code By Operating The Hand Key.
National Archives and Records Administration
INTERNATIONAL MORSE CODE, HAND SENDING
Department of Defense. Department of the Army. Office of the Chief Signal Officer. (09/18/1947 - 02/28/1964)
ARC Identifier 36813 / Local Identifier 111-TF-3697.
10 сен 2024
