1. Adair, R., Physics of baseball, Kinokuniya-Shoten (1996), (in Japanese).
2. ASTM, Standard test method for measuring baseball bat performance factor, F1881 (1998), pp.1-4.
3. ASTM, Standard test method for measuring the coefficient of restitution (COR) of baseballs and softballs, F1887 (2002a), pp.1-3.
4. ASTM, Standard test method for measuring high-speed bat performance, F2219 (2002b), pp.1-7.
5. Cross, R., Impact of a ball with a bat or racket, American Association Journal of Physics Teachers, Vol.67, No.8 (1999), pp.692-702.