Manual prático de rádio e televisão / P. Hémardinquer
Moe's Principle an econometric investigation intended as an aid in dimensioning and managing telephone plant : Theory and tables / Arne Jensen
Telephony : a detailed exposition of the telephone exchange systems of the British Post Office / J. Atkinson
100 Jahre Telephonie in Österreiche : Geschichte und Geschichten / Christine Kainz et al.; int. Karl Lausecker