Etudaiye-Muhtar, O. F., and R. Ahmad. “Empirical Evidence of Target Leverage, Adjustment Costs and Adjustment Speed of Non-Financial Firms in Selected African Countries”. International Journal of Economics and Financial Issues, vol. 5, no. 2, Apr. 2015, pp. 482-8, https://www.econjournals.com/index.php/ijefi/article/view/1133.