RT Journal Article SR Electronic T1 EBM teaching tip: Using lollies to show (non) concealment of allocation JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 5 OP 5 DO 10.1136/ebm.11.1.5-a VO 11 IS 1 A1 Tari Turner A1 Claire Harris YR 2006 UL http://ebm.bmj.com/content/11/1/5.2.abstract AB