Books Covering the X-2 Program
Technical Review of the X-2
The Fastest Man Alive
First of the Spacement - Iven Kincheloe, Jr.
The X-Planes: X-1 to X-45
X Plane Crashes
X-15 - The World's Fastest Rocket Pland and the Pilots Who Ushered in the Space
If you know of any other books or resources covering the X-2, please email me, and I'll put it up on the site.