Bahill, A. Terry; Baldwin, David G.; Venkateswaran, Jayendran (2005). "Predicting a Baseball's Path: A batter watches the pitcher's motion plus the spin on the ball to calculate when and where it will cross the plate". American Scientist. 93 (3): 218–225. JSTOR27858576. S2CID14223113.
Bahill, A. Terry; Baldwin, David G.; Venkateswaran, Jayendran (2005). "Predicting a Baseball's Path: A batter watches the pitcher's motion plus the spin on the ball to calculate when and where it will cross the plate". American Scientist. 93 (3): 218–225. JSTOR27858576. S2CID14223113.