Columbia subject headings:
Harvard subject headings:
Authors, Latin--Correspondence
Emperors--Rome--Correspondence.
Ethics--Early works to 1800
Fronto, Marcus Cornelius--Correspondence.
Life--Early works to 1800
Marcus Aurelius, Emperor of Rome, 121-180--Correspondence.
Orators--Rome--Correspondence.
Stoics--Early works to 1800.
Princeton subject headings:
Ethics--Early works to 1800.
Life--Early works to 1800.
Stoics--Early works to 1800.