<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/2012/01/19/120119093001_jp_keystone304x171_reuters.jpg>
<http://www.bbc.com/mundo/ultimas_noticias/2014/01/140131_ultnot_eeuu_keystone_departamento_estado_tsb.shtml>