Columbia subject headings:
Harvard subject headings:
Arts, Modern--19th century--Congresses.
Arts, Modern--20th century--Congresses
Middle Ages in art--Congresses.
Princeton subject headings:
Arts, German--Congresses.
Arts, Modern--20th century--Germany--Congresses.
German literature--19th century--History and criticism--Congresses.
German literature--20th century--History and criticism--Congresses.
German literature--Middle High German, 1050-1500--History and criticism--Congresses.