1. Working Group on Screening for Neural Tube Defects. Report,1979
2. Maternal plasma alpha-fetoprotein screening for fetal neural tube defects;Brock, D.J.H.; Scrimgeour, J.B.; Steven, J.; Barron, L.; Watt, M.;Br J Obstet Gynaecol,1978
3. Alphafetoprotein in the antenatal diagnosis of open neural tube defects;Wald, N.J.; Cuckle, H.S.;Bry Hosp Med,1980
4. An assessment of the hazards of amniocentesis. Br.7 Obstet Gynaecol;on Amniocentesis, Medical Research Council Working Party,1978
5. A critical evaluation of sonar "crown rump length";Robinson, H.P.; Fleming, J.E.E.;measurements. Bry Obstet Gynaecol,1975