1. 'Oral Health Promotion, Risk Factors, and Molecular Epidemiology Branch, National Institute of Dental Research, 45 Center Drive MSC 6401, Room 4AS-13B, National Institutes of Health, Bethesda, Maryland 20892-6401
2. Departments of Medical Information Science and Statistics, University of Illinois at Urbana
3. Clinical Dental Research Center, University of Minnesota, Minneapolis
4. Department of Biomathematics, M.D. Anderson Cancer Center, Houston, Texas