Columbia subject headings:
Biblioteca ambrosiana--History.
Biblioteca apostolica vaticana--History.
Librarians--Italy--Biography.
Librarians--Italy--Correspondence.
Mai, Angelo, 1782-1854.
Harvard subject headings:
Librarians--Italy--Biography.
Librarians--Italy--Correspondence.
Mai, Angelo, 1782-1854.
Princeton subject headings:
Mai, Angelo, 1782-1854.