<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef-1.bbci.co.uk/news/560/media/images/55816000/jpg/_55816147_r9800211-dark_matter_distribution-spl.jpg>
<http://www.bbc.co.uk/news/science-environment-18503703?postId=112850853>