Columbia subject headings:
Austro-Marxist school--Congresses.
Bauer, Otto, 1881-1938.
Communism--Congresses.
Socialism--Austria--Congresses.
Socialism--Congresses.
Harvard subject headings:
Bauer, Otto, 1881-1938.
Communism--Congresses
Socialism--Austria--Congresses.
Socialism--Congresses
Princeton subject headings:
Bauer, Otto, 1881-1938.
Communism--Congresses.
Socialism--Austria--Congresses.
Socialism--Congresses.