Waldron, M., Worsfold, P., Twist, C., & Lamb, K. (2011). Concurrent validity and test–retest reliability of a global positioning system (GPS) and timing gates to assess sprint performance variables. Journal of Sports Sciences, 29(15), pp. 1613-1619. doi:10.1080/02640414.2011.608703

Waldron, Mark, Paul Worsfold, Craig Twist, and Kevin Lamb. "Concurrent Validity and Test–retest Reliability of a Global Positioning System (GPS) and Timing Gates to Assess Sprint Performance Variables." Journal of Sports Sciences 29, no. 15 (2011): 1613-1619.

Waldron, Mark, Paul Worsfold, Craig Twist, and Kevin Lamb. "Concurrent Validity and Test–retest Reliability of a Global Positioning System (GPS) and Timing Gates to Assess Sprint Performance Variables." Journal of Sports Sciences 29.15 (2011): 1613-1619.