1. Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas
2. Department of Internal Medicine, University of Minnesota School of Medicine, Minneapolis
3. Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas3Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas
4. Division of Cardiology, Medical College of Wisconsin, Milwaukee
5. University of Texas Southwestern Medical Center Library, Dallas