Opiew, Otojo, Bekalu Ferede, and Dereje Daksa. “The Principals”. International Journal of Sciences: Basic and Applied Research (IJSBAR) 34, no. 3 (July 17, 2017): 88–108. Accessed May 4, 2024. https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/7528.