<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef-1.bbci.co.uk/news/ws/560/amz/worldservice/live/assets/images/2014/05/26/140526155240_boko_haram_protests_girls_304x171_getty.jpg>
<http://www.bbc.com/mundo/noticias/2014/05/140528_eeuu_obama_discurso_exterior_guerra_tsb.shtml>