I bought Jeffrey Richelson’s Spying on the Bomb: American Nuclear Intelligence from Nazi Germany to Iran and North Korea.
The book is amazing, particularly the chapter dedicated to the 1979 “flash” over the South Atlantic that may have been a nuclear test.
The National Security Archive, where Richelson is a Senior Fellow, has placed online some of the supporting documents related to the French and South African nuclear programs.
I just got a copy myself. The Soviet sections are instructive when considered in the context of current US-Russian threat reduction cooperation. As a supplement, I highly recommend “The Cold War Atomic Intelligence Game, 1945-70” by Oleg Bukharin in Studies in Intelligence (http://www.cia.gov/csi/studies/vol48no2/article01.html).
I’m wondering exactly what you found “amazing” about the chapter on the 1979 double-peaked flash.