Obaro, Ohwojero, Obaro Chiamaka, and Othetheaso, Oghenero. “MANAGEMENT DEVELOPMENT AND EMPLOYEE EFFECTIVENESS OF OIL FIRMS IN NIGER DELTA, NIGERIA”. GPH-International Journal of Business Management 9, no. 5 (June 18, 2026): 113-131. Accessed June 20, 2026. https://gphjournal.org/index.php/bm/article/view/2472.