Columbia subject headings:
Wagner, Richard, 1813-1883--Influence--Congresses.
Harvard subject headings:
Wagner, Richard, 1813-1883--Appreciation--Europe--History--20th century--Congresses.
Wagner, Richard, 1813-1883--Appreciation--France--History--20th century--Congresses.
Wagner, Richard, 1813-1883--Criticism and interpretation--Congresses.
Wagner, Richard, 1813-1883--Influence--Congresses.
Princeton subject headings:
Wagner, Richard, 1813-1883--Influence--Congresses.