Impact of graphic and text warnings on cigarette packs: findings from four countries over five years
R Borland, N Wilson, G T Fong, D Hammond, K M Cummings, H-H Yong, W Hosking, G Hastings, J Thrasher, A McNeill
Tobacco Control Oct 2009, 18 (5) 358-364; DOI: 10.1136/tc.2008.028043