3C40 (the Large Cities Climate Leadership Group ). Toronto's atmospheric fund makes sustainability affordable [ EB/OL ]. http://www, c40eities, org/bestpractices/ energy/ toronto_ fund. jsp. 2008 - 11 - 04.
4C40 (the Large Cities Climate Leadership Group). Berkeley's building standards mandate increases efficiency and pays back householders in two years [ EB/OL]. http ://www. c40cities, org/ bestpraetiees/buildings/berkeley_standards, jsp. 2007 -04 - 15.
5C40 (the Large Cities Climate Leadership Group ). Freiburg Germany-Cutting home energy consumption by 80% [ EB/OL ] http://www, c40cities, org/bestpractices/ buildings/ freiburg housing, jsp. 2008 - 11 - 04.
6C40(the Large Cities Climate Leadership Group). Seattle sets the standard for US Green Buildings [ EB/OL ]. http ://www. c40cities. org/bestpractices/buildings/seattle_green, jsp. 2007 -04 - 14.