RT Journal Article SR Electronic T1 Epidemiology of Anencephalus and Spina Bifida JF Archives of Disease in Childhood JO Arch Dis Child FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 580 OP 580 DO 10.1136/adc.55.7.580-a VO 55 IS 7 A1 Smithells, R W YR 1980 UL http://adc.bmj.com/content/55/7/580.2.abstract AB