The teleprinter : commercial typewriter keyboard: maintenance instructions / Creed and Company Limited
Description, principle of operation and maintenance instructions : combined teleprinter keyboard perforator and automatic transmitter, teleprinter keyboard perforator / Creed and Company Limited
Palestras profissionais [nº46] Uma circunscrição técnica / Humberto Guerreiro; Administração-Geral dos Correios, Telégrafos e Telefones