<https://www.universoastronomia.com/2016/07/05/le-nubi-colorate-rho-ophiuchi/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.universoastronomia.com/2016/07/05/le-nubi-colorate-rho-ophiuchi/>