Columbia subject headings:
Street-railroads--France--Paris--History--Exhibitions.
Subways--France--Paris--History--Exhibitions.
Harvard subject headings:
Street-railroads--France--Paris--History--Exhibitions.
Subways--France--Paris--History--Exhibitions.
Princeton subject headings:
Street-railroads--France--Paris--History--Exhibitions.
Subways--France--Paris--History--Exhibitions.