Agusrly, Chandra, et al. “Relationship Between Staging and Carcinoembryonic Antigen Serum Levels In Colorectal Cancer Patients’”. Journal of Endocrinology, Tropical Medicine, and Infectious Disease (JETROMI), vol. 2, no. 3, Aug. 2020, pp. 118-23, doi:10.32734/jetromi.v2i3.3959.