1. Keith, S.
, 1982, Subtractive and Additive Differential Gear Reduction System, US Patent No. 4338830A.
2. Fundamental Analysis of Cycloid Ball Reducer (1st Report) Motion Principle;Terada;JSPE,1988
3. Fundamental Analysis of Cycloid Ball Reducer (2nd Report) Radius of Curvature and Pressure Angle;Terada;JSPE,1990
4. Kenji, I.
, 1997, Ball-rolling type torque Transmission Device, US Patent No. 5683323A.
5. Fundamental Analysis of a Cycloid Ball Reducer (5th Report)-Development of a two Stage Type Reduction Mechanism;Terada;JSPE,2009