<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef.bbci.co.uk/news/ws/560/amz/worldservice/live/assets/images/2014/06/16/140616073806_gazprom_304x171_reuters.jpg>
<http://www.bbc.com/mundo/ultimas_noticias/2014/06/140616_ultnot_gazprom_ucrania_cumple_ultimatum_yv.shtml>