BAYSAL, Çağlar, Ülkü DAĞLI, Ahmet TEZEL, Azmi SERİN, and Aysel ÜLKER. 1997. “Interobserver Variation of Endoscopic Activity Index in Ulcerative Colitis”. Turkish Journal of Gastroenterology 8 (2):232-36. https://www.turkjgastroenterol.org/index.php/tjg/article/view/790.