BLOOD CA19-9 LEVELS, ENDOSCOPIC APPEARANCE, HISTOPATHOLOGIC EVALUATION OF BIOPSIES FROM EDGE AND AROUND MUCOSA IN GASTRIC ULCERS - KARA, B.; ÜNSAL, B.; ALTINAY, Z. A.; KARAOĞLU, A. Ö.; YAZICIOĞLU, N.; KARACA, H.; KOŞAY, S. (Turkish Journal of Gastroenterology, 1993)