Columbia subject headings:
Harvard subject headings:
Caligula, Emperor of Rome, 12-41.
Monetary policy--Rome--History--Caligula, 37-41.
Princeton subject headings:
Caligula, Emperor of Rome, 12-41.
Mints--France--Lyon--History.
Mints--Rome--History.
Monetary policy--Rome--History.
Money--Rome--History.