George G. Rhoads

Epidemiology of vomiting in early pregnancy

M. Klebanoff, P. Koslowe, R. Kaslow, 1985, Obstetrics and gynecology.

Maternal vitamin levels during pregnancies producing infants with neural tube defects.

M. Forman, W. Blaner, J. Tuomilehto, 1992, The Journal of pediatrics.