<http://www.w3.org/1999/02/22-rdf-syntax-ns#rest>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#nil>
<http://www.bbc.com/mundo/ultimas_noticias/2014/06/140609_ultnot_mexico_prohiben_circos_con_animales_an.shtml>