Gbatu, A. P., Z. Wang, P. K. Wesseh, Jr, and I. Y. R. Tutdel. “Asymmetric and Dynamic Effects of Oil Price Shocks and Exchange Rate Fluctuations: Evidence from a Panel of Economic Community of West African States (ECOWAS)”. International Journal of Energy Economics and Policy, vol. 7, no. 3, July 2017, pp. 1-13,