<https://letteramodello.com/lettera-di-ringraziamento-allo-sponsor-come-scrivere-esempio-e-fac-simile>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://schema.org/WebPage>
<https://letteramodello.com/lettera-di-ringraziamento-allo-sponsor-come-scrivere-esempio-e-fac-simile>