8Mosley BS, Hobbs CA, Flowers BS et al. Folic acid and the decline in neural tube defects in Arkansas [ J] . J Ark Med Soc, 2007, 103 (10) : 247.
9McGovem E, Moss H, Grewal Get al. Factors affecting the use of folic acid supplements in pregnant women in Glassgow [ J ] . Br J Gen Pract, 1997, 47 (423): 635.
10French MR, Barr SI, Levy - Milne R. Folate intakes and awareness of folate to prevent neural tube defects : a survey of women living in Vancouver, Canada [J]. J Am Diet Assoc, 2003, 103 (2) : 181.
