%0 Journal Article %A Garfield Mahood %T Principles for effective tobacco warning systems: the USA gets a failing grade %D 2021 %R 10.1136/tobaccocontrol-2020-055961 %J Tobacco Control %P 1-3 %V 30 %N 1 %U https://tobaccocontrol.bmj.com/content/tobaccocontrol/30/1/1.full.pdf