1. UK Centre for Tobacco and Alcohol Studies; Wolfson Institute of Preventive Medicine; Queen Mary University of London; London UK
2. Institute of Social and Preventive Medicine; Faculty of Medicine; University of Geneva; Geneva Switzerland
3. Division of Clinical Pharmacology and Experimental Therapeutics; Departments of Medicine and Bioengineering & Therapeutic Sciences; School of Medicine; University of California; San Francisco CA USA
4. Center for the Study of Tobacco Products; Department of Psychology; Virginia Commonwealth University; Richmond VA USA