<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef.bbci.co.uk/news/560/media/images/57328000/jpg/_57328881_c0074043-human_papillomavirus_particles,_tem-spl.jpg>
<http://www.bbc.com/news/health-16185516>