RT Journal Article SR Electronic T1 QUESTION 2 JF Archives of Disease in Childhood JO Arch Dis Child FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 323 OP 324 DO 10.1136/adc.2008.154443 VO 94 IS 4 A1 Veronica B Kelly A1 A Salt YR 2009 UL http://adc.bmj.com/content/94/4/323.abstract AB