1Patterns and trends:New York State energy profiles (1993-2007) [EB/OL]. http://www.nyserda. org/.
2Tokyo metropolitan government, the environment of Tokyo 2006, chapter 2 comparison of cities in the world, 2006 [ EB/OL ]. http: /// www2. kankyo. metro. tokyo. jp/.
3BERR, UK energy in Brief 2008, A national statistics publication[EB/OL], http: //www. berr. gov. uk/.