1. Centre for Tobacco Dependence, 3rd Medical Department, Department of Endocrinology and Metabolism, First Faculty of Medicine Charles University in Prague and General University Hospital in Prague Czech Republic
2. Institute of Hygiene and Epidemiology, First Faculty of Medicine Charles University and General University Hospital Prague Czech Republic
3. Institute of Biostatistics and Analyses at the Faculty of Medicine and the Faculty of Science Masaryk University Brno Czech Republic
4. Behavioral Health and Wellness Program University of Colorado Anschutz Medical Campus Aurora CO USA