Cueto HT, Riis AH, Hatch EE, Wise LA, Rothman KJ, Sørensen HT, Mikkelsen EM. Folic acid supplementation and fecundability: a Danish prospective cohort study. Eur J Clin Nutr. 2016 Jan;70(1):66-71. doi: 10.1038/ejcn.2015.94
Cann CI, Fried MP, Rothman KJ. Epidemiology of squamous-cell cancer of the head and neck. Otolaryngol Clin N Am. 1985 Aug 1;18(3):367-88.