GovernmentNov 1951
Project Grudge and Blue Book status reports
Starting in November 1951, the reactivated Project Grudge, renamed Blue Book in March 1952, issued a series of 12 classified status reports on its work. They were declassified in 1960 but, per the Condon Report, were hard to obtain until NICAP published them in 1968.
Photo: US Air Force, Public domain