Columbia subject headings:
Poland--Boundaries--Soviet Union.
Soviet Union--Boundaries--Poland.
Harvard subject headings:
Poland--Boundaries--Soviet Union
Soviet Union--Boundaries--Poland.
Princeton subject headings:
Poland--Boundaries--Soviet Union.
Poland--History--Occupation, 1939-1945.
Soviet Union--Boundaries--Poland.
World War, 1939-1945--Territorial questions--Poland.