SEVİNİR, Şeniz, et al. “THE RESULTS OF UPPER GASTROINTESTINAL TRACT ENDOSCOPY IN 3712 CASES”. Turkish Journal of Gastroenterology, vol. 4, no. 1, Jan. 1993, pp. 102-6, https://turkjgastroenterol.org/index.php/tjg/article/view/247.