Okoli, T. T., D. D. Tewari, and E. G. N.O. “Assessing the Impact of Skilled Labor on Output Growth in South Africa: An ARDL Bound Testing Approach”. Journal of Economics and Behavioral Studies, Vol. 10, no. 2(J), May 2018, pp. 209-18, doi:10.22610/jebs.v10i2(J).2230.