Columbia subject headings:
Harvard subject headings:
Gruppa "Osvobozhdenie truda"--History--Congresses.
Plekhanov, Georgiĭ Valentinovich, 1856-1918--Congresses.
Princeton subject headings:
Plekhanov, Georgiĭ Valentinovich, 1856-1918--Congresses.
Russia--History--Philosophy--Congresses.