(7) http://commons.wikimedia.org/wiki/Image:
Opec_Organization_of_the_Petroleum_Exporting_Countries_countries.png.
GNU-FDL.(8) http://commons.wikimedia.org/wiki/Image:Hiking_at_Mt._Four_Girls.jpg.
CC-BY-SA 2.5.(9) http://commons.wikimedia.org/wiki/Image:Gulf_Offshore_Platform.jpg.
CC-BY 2.0.(10) http://en.wikipedia.org/wiki/Image:USenergy2004.jpg. Public Domain.
