7.1 Worldwide Telecommunications Industry Revenues සංරක්ෂණය කළ පිටපත 28 මාර්තු 2010 at the Wayback Machine, Internet Engineering Task Force, June 2010.↑ Introduction to the Telecommunications Industry, Internet Engineering Task Force, June 2012.↑ The Atlantic Cable, Bern Dibner, Burndy Library Inc., 1959↑ Arthur C. Clarke. Voice Across the Sea, Harper & Brothers, New York City, 1958.↑ Brown, Travis (1994). Historical first patents: the first United States patent for many everyday things (illustrated ed.). University of Michigan: Scarecrow Press. p. 179. ISBN 978-0-8108-2898-8.↑ Connected Earth: The telephone සංරක්ෂණය කළ පිටපත 21 දෙසැම්බර් 2008 at the Wayback Machine, BT, 2006.↑ History of AT&T සංරක්ෂණය කළ පිටපත 6 සැප්තැම්බර් 2008 at the Wayback Machine, AT&T, 2006.↑ "Significant Achievements in Space Communications and Navigation, 1958–1964" (PDF). NASA-SP-93. NASA. 1966. pp. 30–32. සම්ප්‍රවේශය 31 ඔක්තෝබර් 2009.↑  «Numérique : le cinéma en mutation», Projections, 13,