Concepts for Detection of Extraterrestrial Life, NASA (1964)
https://anonfile.com/c0dep2T4ma/Concept ... A-1964_pdf

Note #1:
-- This document is one small part of a collection I have on Majestic-12.
-- Although MJ-12 is not the subject of the document, it was created/published by NASA in 1964.
-- The document was either declassified or unclassified, but somehow part of MJ-12 (& NASA)

Note #2:
-- I thought this was an interesting read... even if you just flip through it or skip around (since it was published in 1964),
-- There are interesting diagrams with labels, & explanation.
-- The Table of Contents is interesting; parts of it almost sound like science-fiction.