Columbia subject headings:
Welk, Ehm, 1884-1966--Congresses.
Harvard subject headings:
Welk, Ehm, 1884-1966--Congresses.
Welk, Ehm, 1884-1966--Criticism and interpretation--Congresses.
Princeton subject headings:
Welk, Ehm, 1884-1966--Criticism and interpretation--Congresses.