Columbia subject headings:
Harvard subject headings:
Ardennes (France)--History, Military--20th century.
France--History--German occupation, 1914-1918
Germany. Heer--History--20th century.
World War, 1914-1918--Campaigns--France--Ardennes.
World War, 1914-1918--France--Ardennes.
Princeton subject headings:
Ardennes (France)--History, Military--20th century.
France--History--German occupation, 1914-1918.
Germany. Heer--History--20th century.
World War, 1914-1918--Campaigns--France--Ardennes.
World War, 1914-1918--France--Ardennes.