et al., D. T. N. H. “Impacts of External Financing on The Risk Level of Viet Nam Software Industry During and After The Global Crisis 2007-2009”. International Journal of Advanced Science and Technology, Vol. 29, no. 04, Feb. 2020, pp. 1326 -35, http://sersc.org/journals/index.php/IJAST/article/view/5197.