Usoro, A. E. . ., Yusuf, W. A. . ., & Okafor, B. O. N. (2020). Nexus between Non-Oil Sectoral Contribution and Economic Growth in Nigeria 1981-2018. The Economics and Finance Letters, 7(1), 13–22. https://doi.org/10.18488/journal.29.2020.71.13.22