Columbia subject headings:
Opera--Europe.
Theater architecture--Europe--Pictorial works.
Theater in art.
Theaters--Europe--Pictorial works.
Harvard subject headings:
Opera--Europe
Theater architecture--Europe--Pictorial works.
Theater in art.
Theaters--Europe--Pictorial works.
Princeton subject headings:
Opera--Europe.
Theater architecture--Europe.
Theaters in art.
Theaters--Europe.