Wang, J.-N., Hsu, Y.-T., & Liu, H.-C. (2014). How useful are the Various Volatility Estimators for Improving GARCH-based Volatility Forecasts? Evidence from the Nasdaq-100 Stock Index. International Journal of Economics and Financial Issues, 4(3), 651–656. Retrieved from https://econjournals.com.tr/index.php/ijefi/article/view/863