<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef.bbci.co.uk/news/560/media/images/62939000/jpg/_62939283_c0062815-juvenile_raven_corvus_corax_displaying-spl.jpg>
<http://www.bbc.com/news/science-environment-19623929>