1. Liver Diseases Branch National Institute of Diabetes and Digestive and Kidney Diseases National Institutes of Health Bethesda Maryland USA
2. Department of Internal Medicine Medstar Washington Hospital Center Washington DC USA
3. Division of Library Services National Institutes of Health Library National Institutes of Health Bethesda Maryland USA
4. Biostatistics Program, Office of the Director National Institute of Diabetes and Digestive and Kidney Diseases National Institutes of Health Bethesda Maryland USA