Felton, James, Dan McLaughlin, and Woongsun Yoo. “The Impact of COVID-19 on Commodity and S&P 500 Sector Return Volatility”. Journal of Applied Business and Economics 26, no. 3 (August 7, 2024). Accessed October 19, 2024. https://articlegateway.com/index.php/JABE/article/view/7149.