Telephone central office set TC-10 - USA Voorschrift, Technical Manual, 11-338 Telephone Terminal Set TC-21 (N) (Carrier) - USA Voorschrift, Technical Manual, 11-341 technical manual Telephone repeater TP-14 - USA voorschrift Technical Manual 11-2007 Telephone central office set TC-12 - USA Voorschrift, Technical Manual, 11-336 Telephone central office set TC-2 - USA Voorschrift, Technical Manual, 11-340 Principles of long distance telephone and telegraph transmission - USA Voorschrift, Technical Manual, 11-475 Switchboard BD-96 : repair instructions operational requirements - USA Voorschrift, Technical Manual, 11-4314 Operating practices for army administrative telephone switchboards - USA Voorschrift, Technical Manual, 24-210 Ringing equipments EE-100-T1, EE-100-A (voice frequency) and EE-101-A (voice frequency) : repair instructions operational requirements - USA Voorschrift, Technical Manual, 11-4409 Signal : Commercial telephone, telegraph and electric time service, general - USA Voorschrift, Army Regulations, No. 105-30