A zinger is one argument so impressive that all alone it says the document is authentic. The title of the first document is Relationship with Inhabitants of Celestrial Bodies. Celestrial should have been Celestial. This is probably a copy of a carbon copy of a draft prepared by a secretary from dictation, and the secretary did not know how to spell this word. Generally, forensic examiners find that errors present in documents tend to indicate authenticity instead of lack of authenticity.
Fakers usually try to make sure they're perfect.
It has an elite type note with initials of Vannevar Bush at the end. This is the first document to use the phrase Extraterrestrial Biological Entities, or EBEs. It says the presence of unidentified spacecraft is accepted as de facto by the military and this is in June 1947. Those are the subjects of this six-page document. On the first page of the six-page document, note the top secret classification.