Columbia subject headings:
Poland--Social conditions--1980-1989--Congresses.
Social change--Poland--Congresses.
Szczepański, Jan, 1913-2004--Congresses.
Harvard subject headings:
Poland--Social conditions--1980---Congresses.
Social change--Poland--Congresses
Szczepański, Jan, 1913---Congresses.
Princeton subject headings:
Poland--Social conditions--1980---Congresses.
Social change--Poland--Congresses.
Szczepański, Jan, 1913-2004--Congresses.