<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef.bbci.co.uk/news/560/media/images/73108000/jpg/_73108900_m8650301-prostate_cancer_cells,_sem-spl.jpg>
<http://www.bbc.co.uk/news/health-26274475>