Columbia subject headings:
Gruppa "Osvobozhdenie truda"--History--Sources.
Socialism--Soviet Union--History--Sources.
Harvard subject headings:
Gruppa "Osvobozhdenie truda."--History--Sources.
Plekhanov, Georgiĭ Valentinovich, 1856-1918.
Socialism--Russia--Sources.
Socialism--Soviet Union--History--Sources.
Zasulich, V. I., 1849-1919.
Princeton subject headings:
Gruppa "Osvobozhdenie truda"--History--Sources.
Socialism--Soviet Union--History--Sources.