Columbia subject headings:
Harvard subject headings:
Picardy (France)--History, Military--20th century--Congresses.
World War, 1914-1918--Campaigns--France--Picardy--Congresses.
Princeton subject headings:
Picardy (France)--History, Military--20th century--Congresses.
World War, 1914-1918--Campaigns--France--Picardy--Congresses.