RT Journal Article SR Electronic T1 Correspondence JF Archives of Disease in Childhood JO Arch Dis Child FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 340 OP 340 DO 10.1136/adc.42.223.340-a VO 42 IS 223 A1 Illingworth, R. S. YR 1967 UL http://adc.bmj.com/content/42/223/340.2.abstract AB