RT Journal Article SR Electronic T1 The normal thymus and how to recognise it JF Archives of disease in childhood - Education & practice edition JO Arch Dis Child Educ Pract Ed FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP ep25 OP ep25 DO 10.1136/adc.2005.087783 VO 91 IS 1 A1 Helen Williams YR 2006 UL http://ep.bmj.com/content/91/1/ep25.abstract AB