Sources

http://nuclearweaponarchive.org/

http://nuclearweaponarchive.org/Usa/Weapons/Wpngall.html

http://nuclearweaponarchive.org/Japan/Hirosh.html

http://www.ushistory.org/us/51f.asp

http://www.history.com/topics/cold-war

http://atomicarchive.com/History/coldwar/

http://www.atomicarchive.com/History/twocities/index.shtml

http://www.atomicarchive.com/History/trinity/index.shtml