Much of the information and images came from the Smithsonian Institution and is in the Public Domain. This information came from the Museum of American History and a the National Air and Space Museum Web sites and from a videocasette:

Hillmann & Carr, Inc. (Producer). (2002). Reinventing the wheel: the continuing evolution of the bicycle [videorecording]. Washington, DC: Smithsonian National Museum of American History, Behring Center

A few books were used as well to add details not in the Smithsonian sources. The additional books used are:

Baranet, N. N. (1973). Bicycling. South Brunswick, : A. S. Barnes and Co.

Bicycling Magazine, editors of (1990). Bicycling Magazine's mountain biking skills.
         Emmaus, PA: Rodale Press

Burke, E. R. (1986). Science of cycling. Champaign, IL: Human Kinetics Publishers, Inc.

Pridmore, J. (1999). Classic American bicycles. Osceola, WI: MBI Publishing Co.

Wagenvoord, J. (1972). Bikes and riders. New York: Van Nostrand Reinhold Co.