SUCCESS AND UTILITY OF SPUTUM INDUCTION IN NON-EXPECTORATING CF SUBJECTS: DATA FROM THE UK CF GENE THERAPY RUN-IN STUDY - Voase, NWG; Davies, G; Reid, PA; Macleod, KA; Dewar, MH; Bell, NJ; Saunders, C; Greening, AP; Cunningham, S; Innes, JA; Alton, EWFW; Davies, JC (B M J PUBLISHING GROUP, 2009)