Tobacco Use Research Center, Philadelphia, Pennsylvania, United States
University of Pennsylvania, Philadelphia, Pennsylvania, United States
University of Pennsylvania, Philadelphia, Pennsylvania, United States
Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, United States
Transdisciplinary Tobacco Use Research Center, Philadelphia, Pennsylvania, United States
Retina Specialists, Towson, Maryland, United States
Ohio State University Eye Physicians & Surgeons-Retina Division, Dublin, Ohio, United States
Texas Retina Associates, Dallas, Texas, United States
University of Pennsylvania Medical Center, Philadelphia, Pennsylvania, United States
University of Pennsylvania, Philadelphia, Pennsylvania, United States