http://www.cbsnews.com/news/ex-snoop-confirms-echelon-network/ second page missing
1999 Ekstra Bladet interview
1988 New Statesman story by Duncan Campbell
July 1988 Cleveland Plain Dealer
House Permanent Select Committee on Intelligence - no report?
http://www.heise.de/tp/artikel/6/6929/1.html
Hyatt, Michael S. (2001). Invasion of Privacy: How to Protect Yourself in the Digital Age. Washington, DC: Regnery Publishing. p. 68. ISBN 0895262878