<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef.bbci.co.uk/news/ws/560/amz/worldservice/live/assets/images/2013/08/28/130828230901_obama_pbs_304x171_pbs_nocredit.jpg>
<http://www.bbc.com/mundo/ultimas_noticias/2013/08/130828_ultnot_obama_siria_ataques_en.shtml>