1. Agency for Natural Resources and Energy Japan, each yeara. Annual Statistics of Gas Industry, Tokyo.
2. Agency for Natural Resources and Energy Japanb, each yearb. Outline of Electric Power Supply and Demand, Tokyo.
3. Energy Efficiency Indicators and Potential Energy Savings in APEC Economies,2002
4. Estimating the linkage between energy efficiency and productivity;Boyd;Energy Policy,2000
5. Cabinet Office, Government of Japan, 2002. Nihon no shakai shihon (Social Capital of Japan), Tokyo.