1. University of California San Francisco, San Francisco, CA, USA
2. Westat, Rockville, MD, USA
3. National Institute on Drug Abuse, Kelly Government Solutions, Bethesda, MD, USA
4. Center for Tobacco Products, U.S. Food and Drug Administration, Silver Spring, MD, USA
5. National Institute on Dental and Craniofacial Research, Bethesda, MD, USA
6. National Institute on Drug Abuse, Bethesda, MD, USA
7. Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA