Labeda, Ibrahim, et al. “The Relationship of Cyclooxygenase -2 (COX-2) Expression With Clinical Presentation, Staging, and Degree of Differentiation in Colorectal Cancer”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 35, no. 1, July 2017, pp. 64-75, https://www.gssrr.org/JournalOfBasicAndApplied/article/view/7734.