Columbia subject headings:
Mühsam, Erich, 1878-1934--Congresses.
Mühsam, Erich, 1878-1934--Friends and associates--Congresses.
Harvard subject headings:
Mühsam, Erich, 1878-1934--Congresses.
Mühsam, Erich, 1878-1934--Friends and associates--Congresses.
Princeton subject headings:
Mühsam, Erich, 1878-1934--Congresses.
Mühsam, Erich, 1878-1934--Friends and associates--Congresses.