RT Journal Article SR Electronic T1 Twins and Higher Multiple Births: A guide to their nature and nurture JF Archives of Disease in Childhood JO Arch Dis Child FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 267 OP 267 DO 10.1136/adc.69.2.267-b VO 69 IS 2 A1 Coombs, R C YR 1993 UL http://adc.bmj.com/content/69/2/267.3.abstract AB