<http://centroufologicosiciliano.blogspot.com/2014/01/come-costruire-un-disco-volante.html>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://centroufologicosiciliano.blogspot.com/2014/01/come-costruire-un-disco-volante.html>