1. American Psychological Association (2017). Education and socioeconomic status. http://www.apa.org/pi/ses/resources/publications/education.aspx , accessed: 2017-06-22.
2. Andridge, R.R. (2011). Quantifying the impact of fixed effects modeling of clusters in multiple imputation for cluster randomized trials. Biometrical Journal, 53(1), 53–74. https://doi.org/10.1002/bimj.201000140 .
3. Asparouhov, T., & Muthén, B (2010). Multiple imputation with mplus. MPlus Web Notes https://www.statmodel.com/download/Imputations7.pdf .
4. Bartlett, J.W., Seaman, S.R., White, I.R., & Carpenter, J. R. (2015). Multiple imputation of covariates by fully conditional specification: Accommodating the substantive model. Statistical Methods in Medical Research, 24 (4), 462–487. https://doi.org/10.1177/0962280214521348 .
5. Bates, D., Maechler, M., Bolker, B., Walker, S., Christensen, R.H.B., Singmann, H., Dai, B., Grothendieck, G., & Green, P. (2016). lme4: Linear Mixed-Effects Models using ‘Eigen’ and S4. http://cran.r-project.org/web/packages/lme4/index.html , r package version 1.1-12.