Columbia subject headings:
Leaflets dropped from aircraft--Bibliography--Catalogs.
Propaganda, British--Bibliography--Catalogs.
World War, 1914-1918--Propaganda--Bibliography--Catalogs.
Harvard subject headings:
Leaflets dropped from aircraft--Bibliography--Catalogs.
Propaganda, British--Bibliography--Catalogs.
World War, 1914-1918--Propaganda--Bibliography--Catalogs.
Princeton subject headings: