Columbia subject headings:
Oldenburg (Grand Duchy)--Civilization.
Oldenburg (Grand Duchy)--History.
Peter Friedrich Ludwig, Duke of Oldenburg, 1755-1829--Correspondence.
Harvard subject headings:
Oldenburg (Germany)--Civilization.
Oldenburg (Germany)--Kings and rulers--Correspondence.
Painters--Germany--Correspondence.
Peter Friedrich Ludwig, Duke of Oldenburg, 1755-1829--Correspondence.
Tischbein, Johann Heinrich Wilhelm, 1751-1829--Correspondence.
Princeton subject headings:
Oldenburg (Germany)--Civilization.
Oldenburg (Germany)--Kings and rulers--Correspondence.
Painters--Germany--Correspondence.
Peter Friedrich Ludwig, Duke of Oldenburg, 1755-1829--Correspondence.
Tischbein, Johann Heinrich Wilhelm, 1751-1829--Correspondence.