Hi anyone here know where to find the 10th and final peice of history in dead money is, I just want to know if it's a glitch or not and where it is?

That depends on where you got the other bits, although if it's the one I'm thinking of one of the companions has it and you have to deal with him a certain way to get it.

http://fallout.wikia.com/wiki/History%27s_Sake