You can buy all of these books easily on Amazon, Ebay, or just ask your local book seller.
The Airwalker and Bradburry books can be found, with much luck, on Ebay also, becasue they are rare and out of print.
The Rocket Belt Pilot's Manual: A Guide by the Bell Test Pilot
The rocketbelt—a device designed by Bell Aerosystems in the 1960s to be a tactical rescue vehicle for the United States Army—is described here for the first time by one of the machine’s original test pilots. Covering everything from service and fueling to step-by-step directions for use, the guide also includes an in-depth technical background of the flying device and a detailed, easily accessible explanation of the science behind jet propelled flight. Accompanied with photos of each distinct component of the machine and an explanation as to how the parts relate to one another, this unique guide answers more than four decades worth of questions on the rocketbelt and ultimately encapsulates the sheer excitement of flight from a man who experienced it firsthand.