Project Sign: A Classified Assessment of UFO Sightings, Soviet Security Concerns, and Uncertainty

To the point

Project Sign was a classified effort to study military UFO sightings, decide if they indicated extraterrestrials or posed national-security risks, initially leaning toward Soviet aircraft, with some researchers proposing aliens, but keeping multiple plausible explanations, and it was later replaced by newer UFO investigations.

UFO Crash Retrievals: The Complete Investigation

Leonard Stringfield

$Gskyer Refracting Telescope$

Gskyer Refracting Telescope

Exploring the Cosmos with James Webb

Steeven Cadel

The Extraterrestrial Species Almanac: The Ultimate Guide to Greys, Reptilians, Hybrids, and Nordics (MUFON)

Craig Campobasso

Our recommendations from Amazon

britannica.com

Project Sign | American UFO panel | Britannica

Other articles where Project Sign is discussed: Project Blue Book: The first was Project Sign, a classified program that tried to explain a number of military-reported UFO sightings and determine whether they were extraterrestrial in origin, while also considering potential threats to national security, especially those related to possible espionage by the Soviet Union. Project Sign lasted from…