1. Norkin CC, White DJ. Measurement of joint motion: a guide to goniometry. 1st ed. Philadelphia (PA): FA Davis; 1985.
2. Norkin CC, White DJ. Measurement of joint motion: a guide to goniometry. 5th ed. Philadelphia (PA): FA Davis; 2016.
3. Greene WB, Heckman JD. The clinical measurement of joint motion. Rosemont (IL): American Academy of Orthopaedic Surgeons; 1994.
4. Portnoy LG, Watkins MP. Foundations of clinical research: application to practice. Upper Saddle River (NJ): Prentice-Hall; 2000.
5. STATISTICAL METHODS FOR ASSESSING AGREEMENT BETWEEN TWO METHODS OF CLINICAL MEASUREMENT