Aziz, Z. W., A. M. Mahmood, Z. O. Yahiya, and W. M. Taib Al-Nuaimy. “Correlation Between Programmed Cell Death Ligand1 (PD-L1) Expression and Clinical Parameters in Colorectal Carcinoma”. Journal of Contemporary Medical Sciences, vol. 6, no. 4, Aug. 2020, pp. 161-7, doi:10.22317/jcms.v6i4.810.