1. Beazley RH. Aircraft wheel spinner and control. Washington, DC: U.S. Patent and Trademark Office; 1947.
2. Khal S, Khal A. Apparatus for pre-rotating aircraft tires. Washington, DC: U.S. Patent and Trademark Office; 2013.
3. Sweet RM, Gilleran N, Edelson JS, et al. Integrated electric motor and gear in an aircraft wheel. Washington, DC: U.S. Patent and Trademark Office; 2014.
4. Didey A. Landing gear drive systems. Washington, DC: U.S. Patent and Trademark Office; 2014.
5. Karl W. Free Spinning Wheel for Airplanes. Washington, DC: U.S. Patent and Trademark Office; 2014.