Telephony : a detailed exposition of the telephone system of the British Post Office / T. E. Herbert; W. S. Procter
A telephone development project / Sven Lönnström; Folke Marklund; Ingemar Moo
Dictionary of telephone terms : english-spanish, spanish-english / Automatic Electric International
Compendium of the technical recommendations : issued by CCIF, CCIT, CCIR of the International Telecommunications Union / Automatic Telephone & Electric Co Ltd