MacLeod S, Tkatch R, Kraemer S, Fellows A, McGinn M, Schaeffer J, Yeh CS. The impact of COVID-19 on informal caregivers in the US. Int J Aging Res. 2021 Jan;4(87).
Milunsky A, Morris JS, Jick H, Rothman KJ, Ulcickas M, Jick SS, Shoukimas P, Willett W. Maternal zinc and fetal neural tube defects. Teratology. 1992 Oct 1;46(4):341-8.
Rothman KJ, Fyler DC. Association of congenital heart defects with season and population density. Teratology. 1976 Feb;13(1):29-34.