Columbia subject headings:
Socialism and youth--Poland--History.
Socialists--Poland--Societies and clubs--History.
Towarzystwo Uniwersytetu Robotniczego--History.
Youth--Poland--Societies and clubs--History.
Harvard subject headings:
Socialism and youth--Poland.
Towarzystwo Uniwersytetu Robotniczego--History.
Youth--Poland--Political activity.
Princeton subject headings: