Columbia subject headings:
Harvard subject headings:
Postcards--France
World War, 1914-1918--France--Pictorial works.
World War, 1914-1918--Pictorial works
World War, 1914-1918--Social aspects.
Princeton subject headings:
Postcards--France.
World War, 1914-1918--Art and the war.
World War, 1914-1918--Social aspects.