Columbia subject headings:
Ullmann, Viktor--Criticism and interpretation--Congresses.
Ullmann, Viktor--Philosophy--Congresses.
Harvard subject headings:
Ullmann, Viktor--Criticism and interpretation--Congresses.
Ullmann, Viktor. Kaiser von Atlantis--Congresses.
Princeton subject headings:
Ullmann, Viktor--Criticism and interpretation--Congresses.
Ullmann, Viktor--Philosophy--Congresses.