6BP. Statistical Review of World Energy. London: British Petroleum (BP), 2009.
7Robert K Dixon, Elizabeth McGowan et al. US energy conservation and efficiency policies: Challenges and opportunities. Energy Policy, 2010, doi: 10.1016/j.enpol.2010.01.038.
8Philip Andrews-Speed. China's ongoing energy efficiency drive: Origins, progress and prospects. Energy Policy, 2009, 37: 1331-1344.
9Zhou P, Ang B W. Linear programming models for measuring economy-wide energy efficiency performance. Energy Policy, 2008, 36: 2911-2916.
10Nan Zhou, Mark D Levine, Lynn Price. Overview of current energy-efficiency policies in China. Energy Policy, 2009, doi: 10.1016/j.enpol.2009.08.015.