DUMLU, Şükrü (1997) “CA 19-9 and morphologic criteria in differential diagnosis of malign gastric ulcers”, Turkish Journal of Gastroenterology, 8(2), pp. 197–200. Available at: https://www.turkjgastroenterol.org/index.php/tjg/article/view/782 (Accessed: 1 January 2026).