Folic Acid, Pernicious Anaemia, and Prevention of Neural Tube DefectsLancet 343:307, Wald,N.J.&Bower,C., 1994
Maternal Cocaine Abuse:The Spectrum of Radiologic Abnormalities in the Neonatal CNSAJR 157:1105-1110, Heier,L.A.,et al, 1991