Columbia subject headings:
World War, 1914-1918--Aerial operations.
World War, 1914-1918--Campaigns--Western Front.
Harvard subject headings:
World War, 1914-1918--Aerial operations
World War, 1914-1918--Campaigns--Western Front
Princeton subject headings:
World War, 1914-1918--Aerial operations.
World War, 1914-1918--Campaigns--Western Front.