Columbia subject headings:
Influenza Epidemic, 1918-1919.
Influenza--History--20th century.
World War, 1914-1918--Health aspects.
Harvard subject headings:
Epidemics--Spain--History--20th century.
Influenza Epidemic, 1918-1919
Influenza--Spain--History--20th century.
World War, 1914-1918--Accidents.
Princeton subject headings:
Influenza Epidemic, 1918-1919.
Influenza--History--20th century.
World War, 1914-1918--Health aspects.