Nathaniel, B. (2014) “Comparative Analysis of Upstream Petroleum Fiscal Systems of Three (3) Petroleum Exporting Countries: Indonesia, Nigeria and Malaysia”, International Journal of Sciences: Basic and Applied Research (IJSBAR), 15(2), pp. 99–115. Available at: https://www.gssrr.org/JournalOfBasicAndApplied/article/view/2657 (Accessed: 6 October 2025).