RT Journal Article SR Electronic T1 Midline mystery 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 216 OP 216 DO 10.1136/archdischild-2012-302212 VO 97 IS 6 A1 Helen Williams YR 2012 UL http://ep.bmj.com/content/97/6/216.abstract AB