Okoth, K. G. ., and J. L. . Barasa. “A Test of the Effect of Macro-Economic Variables on Volatility of Securities Prices: Evidence from Nairobi Securities Exchange”. Operations Research Society of Eastern Africa, Dec. 2014, pp. 114-61, https://orseajournal.udsm.ac.tz/index.php/orsea/article/view/28.