Sinaga, O., D. Roespinoedji, M. H. M. Saudi, and E. K. Ghani. “The Role of Management Accounting Systems, Energy Efficiency and Organizational Innovation in Driving Competitive Advantage and Firm Performance”. International Journal of Energy Economics and Policy, vol. 9, no. 3, Apr. 2019, pp. 395-02, https://www.econjournals.com/index.php/ijeep/article/view/7749.