NSA Technical Journal, Winter 1966 - Vol. XI, No. 1: Communications with Extraterrestrial Intelligence "Archived copy"(PDF). Archived from the original(PDF) on 16 December 2011. Retrieved 27 November 2011.{{cite web}}: CS1 maint: archived copy as title (link)
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NSA Technical Journal, Winter 1966 - Vol. XI, No. 1: Communications with Extraterrestrial Intelligence "Archived copy"(PDF). Archived from the original(PDF) on 16 December 2011. Retrieved 27 November 2011.{{cite web}}: CS1 maint: archived copy as title (link)