Columbia subject headings:
Harvard subject headings:
Lenin, Vladimir Ilʹich, 1870-1924
Luxemburg, Rosa, 1871-1919
Political science--History
Socialism.
Princeton subject headings:
Lenin, Vladimir Ilʹich, 1870-1924.
Luxemburg, Rosa, 1871-1919.
Soviet Union--History--Revolution, 1917-1921.