Columbia subject headings:
Paris (France)--Buildings, structures, etc.--Pictorial works.
Subways--France--Paris--Pictorial works.
Harvard subject headings:
Paris (France)--Buildings, structures, etc.--Pictorial works
Subways--France--Paris--Pictorial works.
Princeton subject headings:
Paris (France)--Buildings, structures, etc.--Pictorial works.
Subways--France--Paris--Pictorial works.