Columbia subject headings:
Kelles-Krauz, Kazimierz, 1872-1905.
Socialism--Philosophy.
Socialism--Poland.
Socialists--Poland--Biography.
Harvard subject headings:
Socialism--Poland
Socialism.
Princeton subject headings:
Kelles-Krauz, Kazimierz, 1872-1902.
Socialism--Philosophy.
Socialism--Poland.
Socialists--Poland--Biography.