Nakpodia, E. D. “Principals’ Supervisory Aptitude of Teachers’ Work Performance in Delta State Secondary Schools, Nigeria”. Journal of Research in Education and Society (JRES) 2, no. 1 (April 1, 2011): 263–274. Accessed September 19, 2024. http://icidr.org.ng/index.php/Jres/article/view/1183.