http://books.google.it/books?id=azC89hLTnboC&printsec=frontcover&dq=dialogo+sui+due+massimi+sistemi&hl=it&sa=X&ei=KI8ET53YBI_tOaKxxO4C&ved=0CDMQ6AEwAA#v=onepage&q=dialogo%20sui%20due%20massimi%20sistemi&f=false
