<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef.bbci.co.uk/news/560/media/images/74372000/jpg/_74372981_c0205666-graphene_structure,_artwork-spl.jpg>
<http://www.bbc.co.uk/news/science-environment-27113732>