Columbia subject headings:
Historical materialism.
Krzywicki, Ludwik, 1859-1941.
Socialism--Poland--History.
Harvard subject headings:
Historical materialism.
Krzywicki, Ludwik, 1859-1941--Contributions in historical materialism.
Krzywicki, Ludwik, 1859-1941.
Socialism--Poland
Socialism--Poland--History
Princeton subject headings:
Dialectical materialism.
Krzywicki, Ludwik, 1859-1941.
Sociologists--Poland--Biography.