Abbreviated NTBT, this 1963 treaty was signed by the U.S., the USSR & the U.K.
[DOC] [TLE] Partial Nuclear Test Ban Treaty - Wikipedia [PAR] The Partial Test Ban Treaty (PTBT) is the abbreviated name of the 1963 Treaty 
Banning ... as the Limited Test Ban Treaty (LTBT) and Nuclear Test Ban Treaty (
NTBT), though ...