<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef.bbci.co.uk/news/560/media/images/73096000/jpg/_73096230_c0163063-european_nitrogen_dioxide_emissions,_2008-spl.jpg>
<http://www.bbc.co.uk/news/science-environment-26257703>