Herle McGowan McGowan, H. M., Nix, R. L., Murphy, S. A., & Bierman, K. L. (2010). Investigating the Impact of Selection Bias in Dose-Response Analyses of Preventive Interventions. PREVENTION SCIENCE, 11(3), 239–251. https://doi.org/10.1007/s11121-010-0169-2