Columbia subject headings:
Harvard subject headings:
Somme (France)--History, Military--20th century.
Somme, 1st Battle of the, France, 1916
World War, 1914-1918--Campaigns--France
Princeton subject headings:
Somme (France)--History, Military--20th century.
Somme, 1st Battle of the, France, 1916.
World War, 1914-1918--Campaigns--France.