RT Journal Article SR Electronic T1 Determining the optimal newborn screening protocol for cystic fibrosis JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP thoraxjnl-2012-201589 DO 10.1136/thoraxjnl-2012-201589 A1 Kevin W Southern YR 2012 UL http://thorax.bmj.com/content/early/2012/02/07/thoraxjnl-2012-201589.abstract AB