1. Center for Global Tobacco Control, Division of Society, Human Development and Health, Harvard School of Public Health, Boston, Massachusetts, USA.
2. Smoking and Lung Cancer Research Center, Hellenic Cancer Society, Athens, Greece.
3. Clinic of Social and Family Medicine, Department of Social Medicine, University of Crete, Heraklion, Greece.
4. Department of Medicine, University of Athens, Greece.
5. Department of Respiratory Medicine, University of Thessaly, Greece.
6. Department of Medicine, Aristotelio University of Thessaloniki, Thessalonkii, Greece.
7. Department of Pulmonary Medicine, General Hospital of Serres, Serres, Greece.
8. Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA.