Story of the indian telegraphs : a century of progress / Krishnalal Shridharani
Esprit ´87 : achievements and impact / Commision of the European Communities
Communications téléphoniques à grande distance [texto policopiado] / International Standard Electric Corporation; M. H. S. Osborne et. al.
Guglielmo Marconi et la radio / Steve Parker; trad. Henri Lilen