Tong, S., M. M. M. Baslom, and H. Z. H. Alsharif. “Investigating Volatility in Saudi Arabia Crude Oil Prices and Its Impact on Oil Stock Market”. International Journal of Energy Economics and Policy, vol. 8, no. 4, July 2018, pp. 338-46, https://econjournals.com/index.php/ijeep/article/view/6849.