Liu X, Hannum E. Early poverty exposure predicts young adult educational outcomes in China. China Econ Rev. 2017 Jul;44:79-97.
Brubaker L, Richter HE, Barber MD, Hsu Y, Rahn DD, Menefee S, Visco A, Spino C, Martin S, Meikle SF. Pelvic floor disorders clinical trials: participant recruitment and retention. Int Urogynecol J. 2013 Jan 1;24(1):73-9.
Parsley (Edwards) TL. Review of the phantom respondents: opinion surveys and political representation. J Off Stat. 1994;10(3):351-5.