NASA US X-Vehicles from the X-1 to the X-50 by Dennis R. Jenkins, Tony Landis, and Jay Miller is a very useful book for reading about all NASA X-Vehicles from the X-1 to the X-50 and many more. This book is a brief guide of history. Download the pdf to learn about all NASA US X-Vehicles.

Some of the Book Contents-

Bell X-1 (First Generation)
Bell X-1 (Second Generation)
Bell X-1E
Bell X-2
Douglas X-3
Northrop X-4
Bell X-5
Consolidated-Vultee X-6
Lockheed X-7
Aerojet General X-8
Bell X-9
North American X-10
Consolidated-Vultee X-11
Consolidated-Vultee X-12
Ryan X-13
Bell X-14
North American X-15
North American X-15A-2