1. Center for Tobacco Research The Ohio State University Wexner Medical Center Columbus Ohio USA
2. Department of Oncology, School of Medicine Georgetown University Washington DC USA
3. Department of Psychology University of Waterloo Waterloo Ontario Canada
4. School of Public Health Sciences University of Waterloo Waterloo Ontario Canada
5. Department of Statistics and Actuarial Science University of Waterloo Waterloo Ontario Canada
6. Department of Oncology, Lombardi Comprehensive Cancer Center Georgetown University Washington DC USA
7. Ontario Institute for Cancer Research Toronto Ontario Canada
8. Department of Psychiatry and Behavioral Sciences Medical University of South Carolina Charleston South Carolina USA
9. Department of Internal Medicine, Medical Oncology Division The Ohio State University Columbus Ohio USA