You know, of course, about the A-bomb, H-bomb and C-bomb because information that they existed had been declassified.
"Project Hush"
Philip Klass
And then, after it was declassified, it had been so far superseded that it was of only antiquarian interest; the textbooks dealt with it only in general terms.
"Uller Uprising"
Henry Beam Piper, John D. Clark and John F. Carr