Calderwood, Lisa. “Improving Between-Wave Mailings on Longitudinal Surveys: A Randomised Experiment on the UK Millennium Cohort Study”. Survey Research Methods 8, no. 2 (July 23, 2014): 99–108. Accessed April 24, 2024. https://ojs.ub.uni-konstanz.de/srm/article/view/5391.