<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef.bbci.co.uk/news/ws/560/amz/worldservice/live/assets/images/2012/12/07/121207013610_sp_kelly_224x280_bbc_nocredit.jpg>
<http://www.bbc.com/mundo/noticias/2012/12/121206_curiosidades_economia_tutores_reyes_en.shtml>