The cable and wireless communications of the world : some lectures and papers on the subject. 1924 - 1939 / Edward Wilshaw, et. al.
Guide to the correction of errors in code (and other) telegrams / The Telegraph Convention
Colección histórico-tecnológica de Telefónica / Rafael Romero Frias; Fundación Arte y Tecnologia (Telefónica)
During six reigns / The General Electric Company Limited of England