Weapon

http://playground.sun.com/~vasya/index.html awesome website, all about knives. About types of knives, materials they are made of, different stills, history, manufacturers, etc. All in Russian though…

http://www.cs.columbia.edu/~smb/nsam-160/pal.html#GS94 A PAL – a “Permissive Action Link” – is the box that is supposed to prevent unauthorized use of a nuclear weapon «<