Aoki, H., and N. Kawamiya. “The Business Structure of Japan’s Electric Industry for 1963-2016: Analysis on the Revenues and Expenditures Throughout before and After the ‘Deregulation’”. International Journal of Energy Economics and Policy, vol. 9, no. 1, Dec. 2018, pp. 316-25, https://www.econjournals.com/index.php/ijeep/article/view/6999.