Rafindadi, Abdulkadir Abdulrashid, and Zakariyah Aliyu Olanrewaju. 2019. “Internal Control System, Sustainable Management and Service Delivery of NGO’s in Nigeria: An Empirical Analysis”. International Review of Management and Marketing 9 (2):89-103. https://econjournals.com/index.php/irmm/article/view/7773.