1. Alpha fetoprotein in the antenatal diagnosis of anencephaly and spina bifida;Brock;Lancet,1972
2. Results and benefits of a maternal serum AFP screening program;Milunsky;JAMA,1984
3. Outcome in patients with unusually high maternal serum alpha fetoprotein levels;Nelson;Am J Obstet Gynecol,1987
4. Maternal serum alpha fetoprotein screening for the detection of neural tube defects;Crandall;West J Med,1983
5. Significance of raised maternal serum alpha fetoprotein in singleton pregnancies with normally formed fetuses;Hamilton;Obstet Gynecol,1985