He, Yiming, and Shaohui Gao. “Gas Consumption and Metropolitan Economic Performance: Models and Empirical Studies from Guangzhou, China”. International Journal of Energy Economics and Policy 7, no. 2 (April 14, 2017): 121–126. Accessed April 25, 2024. https://www.econjournals.com/index.php/ijeep/article/view/3641.