Schmid, Gerhard (2001-07-11), "Report on the existence of a global system for the interception of private and commercial communications (Echelon interception system)", EU temporary committee on the Echelon interception system(PDF), Europaparlamentet, arkiveret fra originalen 26. december 2013, hentet 2011-01-22
web.archive.org
Schmid, Gerhard (2001-07-11), "Report on the existence of a global system for the interception of private and commercial communications (Echelon interception system)", EU temporary committee on the Echelon interception system(PDF), Europaparlamentet, arkiveret fra originalen 26. december 2013, hentet 2011-01-22