Lumbantobing, Herryanto, Leonardo Basa Dairi, Juwita Sembiring, Mabel Sihombing, Betthin Marpaung, Sri Maryuni Sutadi, and Lukman Hakim Zain. “The Profile of Upper Gastrointestinal Endoscopy in Deli Serdang Hospital”. The Indonesian Journal of Gastroenterology, Hepatology, and Digestive Endoscopy 12, no. 1 (January 4, 2011): 34–37. Accessed October 20, 2026. https://ina-jghe.com/index.php/jghe/article/view/301.