9Ren R. and K. Chen. , 1994, An Expenditure Based Bilateral Comparison of Gross Domestic Product between China and the United States [J], Review of Income and Wealth, 40 (4), 377-394.
10The Energy Data and Modeling Center, The Institute of Energy Economics Japan, 2003, Handbook of Energy & Economic Statistics in Japan [M], The Energy Conservation Center, JAPAN.