Nihat OKÇU; Bekir SAMİ UYANIK; Ersin AKARSU; Ebubekir BAKAN; H. Zeki TONBUL. The Importance of Carbonhydrate Antigens (CA 19-9, CA 125), Carcinoembriyonic Antigen (CEA) and Alkaline Phosphatase (AP) in Patients With Gastric and Colorectal Cancer. Turkish Journal of Gastroenterology 2020, 6, 467-471.