<https://davidblancoperez.com/como-hacer-para-que-tus-vendedores-vendan-mas-parte-2/#webpage>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://davidblancoperez.com/como-hacer-para-que-tus-vendedores-vendan-mas-parte-2/>