<http://www.w3.org/1999/02/22-rdf-syntax-ns#first>
<http://ichef.bbci.co.uk/news/ws/560/amz/worldservice/live/assets/images/2013/05/30/130530212907_aaronlevie512.jpg>
<http://www.bbc.com/mundo/noticias/2013/06/130528_aaron_levie_multimillonario_atipico_finde_cch.shtml>