Columbia subject headings:
Architecture--Germany--Frankfurt am Main--History--20th century.
Architecture--Germany--Frankfurt am Main.
Buildings--Germany--Frankfurt am Main.
Harvard subject headings:
Architecture, Modern--20th century--Germany--Frankfurt am Main.
Architecture--Germany--Frankfurt am Main--History.
Architecture--Germany--Frankfurt am Main.
Buildings--Germany--Frankfurt am Main.
Frankfurt am Main (Germany)--Buildings, structures, etc.
Princeton subject headings: