Liu X, Hannum E. Early poverty exposure predicts young adult educational outcomes in China. China Econ Rev. 2017 Jul;44:79-97.
Pueschel SM, Rothman KJ, Ogilby JD. Birth weight of children with down's syndrome. Am J Ment Defic. 1976 Jan;80(4):442-5.
Rothman KJ, Glass RL, Espinal F, Velez H. Caries-free teeth in the absence of fluoride ion. J Public Health Dent. 1972;32(4):225-8. doi: 10.1111/j.1752-7325.1972.tb03977.x