Website: project1947.com (PROJECT 1947, Canterbury,
Connecticut):
(Project Sign (started in 1947))
(Project Sign Air Force)
(Project Grudge (started in 1949))
(Grudge)
(Project Grudge Air Force)
(Project Twinkle (started in 1950))
(Twinkle)
(Project Twinkle Air Force)
(Project Blue Book (started in 1952))
(Blue Book)
(Project Blue Book Air Force)
Wikipedia article: “Project Blue Book”:
(wikimedia.org image)