Columbia subject headings:
Postcards--Germany--Facsimiles.
World War, 1914-1918--Caricatures and cartoons.
Harvard subject headings:
Postcards--Germany.
Postcards.
World War, 1914-1918--Caricatures and cartoons
Princeton subject headings:
Postcards--Germany.
World War, 1914-1918--Caricatures and cartoons.