1. Section of Gastroenterology and Hepatology; Department of Medicine; Baylor College of Medicine; Houston TX USA
2. Houston VA HSR&D Center for Innovations in Quality, Effectiveness and Safety; Michael E. DeBakey Veterans Affairs Medical Center; Houston TX USA
3. The Texas Medical Center Library; Houston TX USA
4. Dan L Duncan Comprehensive Cancer Center; Baylor College of Medicine; Houston TX USA
5. Section of Epidemiology and Population Sciences; Department of Medicine; Baylor College of Medicine; Houston TX USA