<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/blogs/2013/12/131204_blog_un_mundo_feliz_david_cuen_google_plus.shtml?postId=118081469>