Columbia subject headings:
Harvard subject headings:
Book collecting--Poland--History--Congresses.
Polish libraries--Foreign countries--Congresses.
Private libraries--Poland--History--Congresses.
Princeton subject headings:
Book collecting--Poland--History--20th century--Congresses.
Cultural property--Poland--History--20th century--Congresses.
Libraries--Poland--History--20th century--Congresses.
Poland--History--Occupation, 1939-1945--Congresses.
World War, 1939-1945--Destruction and pillage--Poland--Congresses.
World War, 1939-1945--Libraries--Congresses.