Columbia subject headings:
Harvard subject headings:
Theater--England--London--19th century.
Theater--England--London--20th century.
Theater--Europe--History
Theater--Germany--Berlin--19th century.
Theater--Germany--Berlin--20th century.
Princeton subject headings:
Theater--England--London--19th century.
Theater--England--London--20th century.
Theater--Europe--History.
Theater--Germany--Berlin--19th century.
Theater--Germany--Berlin--20th century.