1. Gastroenterology and Endoscopy Unit, S. Elia Hospital, Caltanissetta, Italy
2. Faculty of Medicine, “Kore” University of Enna, Enna, Italy
3. Gastroenterology and Endoscopy Unit, S. Elia-Raimondi Hospital, Caltanissetta
4. University of Cincinnati Libraries, Donald C. Harrison Health Sciences Library, Cincinnati, OH
5. Internal Medicine Residency, University of Connecticut, Farmington, CT
6. Mercy Internal Medicine Service, Trinity Health of New England, Springfield, MA
7. Division of Gastroenterology & Hepatology, CHI Health Creighton University Medical Center, Omaha, NE
8. Gastroenterology & Hepatology, University of Nebraska Medical Center, Omaha, NE
9. Gastroenterology & Hepatology, Emory University Hospital, Atlanta, GA, USA
10. Section of Gastroenterology, Department of Medical Sciences, University of Foggia, Foggia, Italy
11. Division of Gastroenterology, Johns Hopkins Medical Institutions, Baltimore, MD