TY - JOUR AU - Waldron, M; Worsfold, P; Twist, C; Lamb, K TI - Concurrent validity and test-retest reliability of a global positioning system (GPS) and timing gates to assess sprint performance variables JO - J Sports Sci VL - 29 PY - 2011 DO - 10.1080/02640414.2011.608703 SP - 1613 EP - 1619 ER -