Oroye-Okpoudhu, R. Zino. “Mechanisms Used By School Principals to Achieve Effective Instructional Supervision in Delta State Public Secondary Schools, Nigeria”. Journal of Research in Education and Society (JRES) 10, no. 3 (December 30, 2019): 133–143. Accessed September 19, 2024. http://icidr.org.ng/index.php/Jres/article/view/1495.