Gear Technology Magazine
www.geartechnology.com/articles/20819-functions-of-gearing-and-application-of-the-involute-to-gear-teeth

Functions of Gearing and Application of the Involute to Gear Teeth

August 1, 1984
Experience has proven that the involute provides the most satisfactory profile for spur and helical gear teeth, and fulfills the requirements for transmitting smooth, uniform angular motion.