Kellis, E., & Baltzopoulos, V. B. (1999). In vivo determination of the patella tendon and hamstrings moment arms in adult males using videofluoroscopy during submaximal knee extension and flexion. Clinical biomechanics, 14(2), S. 118-124. doi:10.1016/S0268-0033(98)00055-2

Kellis, E., and Vasilios B. Baltzopoulos. "In Vivo Determination of the Patella Tendon and Hamstrings Moment Arms in Adult Males Using Videofluoroscopy During Submaximal Knee Extension and Flexion." Clinical Biomechanics 14, no. 2 (1999): S. 118-124.

Kellis, E., and Vasilios B. Baltzopoulos. "In Vivo Determination of the Patella Tendon and Hamstrings Moment Arms in Adult Males Using Videofluoroscopy During Submaximal Knee Extension and Flexion." Clinical Biomechanics 14.2 (1999): S. 118-124.