Columbia subject headings:
Fortification--France--Lorraine--History.
France--Defenses--History.
Harvard subject headings:
Architecture--France--Lorraine.
Fortification--France--Lorraine--History--19th century.
Fortification--France--Lorraine--History--20th century.
France--History, Military--19th century.
France--History, Military--20th century.
Princeton subject headings: