Heartburn

• Gasterointestinal endoscopy ward, Amir Alam hospital, Tehran university of medical sciences — Tehran, Tehran Province, Iran

• Chang Gung Memorial Hospital — Taipei, Taiwan

• Hueytown, Alabama, United States
• Chandler, Arizona, United States
• Sierra Vista, Arizona, United States
• Tucson, Arizona, United States

• Hueytown, Alabama, United States
• Huntsville, Alabama, United States
• Chandler, Arizona, United States
• Phoenix, Arizona, United States

• Anaheim, California, United States
• Cypress, California, United States
• Overland Park, Kansas, United States

• The University of North Carolina at Chapel Hill — Chapel Hill, North Carolina, United States

• The Catholic University of Korea St. Mary's Hospital — Seoul, South Korea

• Oesophageal Laboratory, GSTT — London, United Kingdom

• Research Site — Athens, Alabama, United States
• Research Site — Tucson, Arizona, United States
• Research Site — Little Rock, Arkansas, United States
• Research Site — Sherwood, Arkansas, United States

Not specified