Christensen T, Riis AH, Hatch EE, Wise LA, Nielsen MG, Rothman KJ, Toft Sorensen H, Mikkelsen EM. Costs and efficiency of online and offline recruitment methods: a web-based cohort study. J Med Internet Res. 2017 Mar 1;19(3):e58. doi: 10.2196/jmir.6716
Gomersall T, Spencer S, Basarir H, Tsuchiya A, Clegg J, Sutton A, Dickinson K. Measuring quality of life in children with speech and language difficulties: a systematic review of existing approaches. Int J Lang Commun Disord. 2015 Jul;50(4):416-35. doi: 10.1111/1460-6984.12147
Williams VSL, Jones LV, Tukey JW. Controlling error in multiple comparisons, with examples from state-to-state differences in educational achievement. J Educ Behav Stat. 1999;24(1):42-69. doi: 10.3102/10769986024001042