Thomas A, Danon L, Christensen H, Northstone K, Smith D, Nixon E, Trickey A, Hemani G, Sauchelli S, Finn A, Timpson N, Brooks-Pollock E. Limits of lockdown: characterising essential contacts during physical distancing. Wellcome Open Res. 2021 May;6:116. doi: 10.12688/wellcomeopenres.16785.1
Williams VSL, Wakeford ME. The predictive validity of the National Teacher Examinations for performance in teacher education programs. Educ Psychol Meas. 1993;53(2):533-9. doi: 10.1177/0013164493053002023