Bismark Addai, Annette Serwaa Agyeman, Adjei Gyamfi Gyimah. “Modelıng the volatılıty of Stock Returns Usıng Arma and Garch Models”. International Journal of Advanced Science and Technology, Vol. 29, no. 7, June 2020, pp. 8465-7, http://sersc.org/journals/index.php/IJAST/article/view/24892.