In 1978, the United States Central Intelligence Agency (CIA) declassified hundreds of documents detailing its investigations into unidentified flying objects (UFOs) in the late 1940s through the 1950s. Today, the agency has decided to do it again and opens its archives of its FOIA UFO collection for skeptics and believers alike to investigate.

This is a list of 10 publications and covering the golden decade of sightings, which runs from 1940 to 1950. The CIA divides its documents into two groups.

The five main CIA documents for believers:

Informed Flying Saucers Over East Germany, 1952
Minutes of UFO branch chief meeting, 1952
Informed flying saucers over Spain and North Africa, 1952
Flying Saucer Reports Survey, 1952
Flying saucers reported on Belgian Congo uranium mines, 1952

The top five CIA documents for skeptics:

Scientific Advisory Panel on Unidentified Flying Objects, 1953
Office Memorandum on Flying Saucers, 1949
Memorandum to the CIA Director on Flying Saucers, 1952
OSI Advisory Group Meeting on UFOs, 1953
Memorandum for the registration of flying saucers, 1952

Whether they are believers or not, this is the time they were waiting to start rummaging. You can enter the documents from this link.