1. Department of Pulmonary Medicine, School of Medicine, Gazi University, Ankara, Turkey
2. Clinic of Chest Diseases, Ankara Ataturk Training and Research Hospital, Ankara, Turkey
3. Department of Pulmonary Medicine, School of Medicine, Ufuk University, Ankara, Turkey
4. Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
5. Department of Pulmonology, Clinical Science Center, St George University School of Medicine, London, UK