<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef.bbci.co.uk/news/560/media/images/65886000/jpg/_65886581_e6700080-tunguska_event_site-spl.jpg>
<http://www.bbc.co.uk/news/science-environment-21459861>