Columbia subject headings:
Excavations (Archaeology)--Poland--Congresses.
Poland--Antiquities--Congresses.
Poland--Historiography--Congresses.
Poland--History--Piast period, 960-1386--Congresses.
Poland--History--To 960--Congresses.
Harvard subject headings:
Poland--History--Historiography.
Poland--History--Piast period, 960-1386
Princeton subject headings: