Wilk, K. A., Andrews, J. R., Arrigo, C. A., Keirns, M. A., & Erber, D. J. (1993). The strength characteristics of internal and external rotator muscles in professional baseball pitchers. The American journal of sports medicine, 21(1), S. 61-66.

Wilk, Kevin A., James R. Andrews, Christopher A. Arrigo, Michael A. Keirns, and Donna J. Erber. "The Strength Characteristics of Internal and External Rotator Muscles in Professional Baseball Pitchers." The American Journal of Sports Medicine 21, no. 1 (1993): S. 61-66.

Wilk, Kevin A., et al. "The Strength Characteristics of Internal and External Rotator Muscles in Professional Baseball Pitchers." The American Journal of Sports Medicine 21.1 (1993): S. 61-66.