Columbia subject headings:
Poland--History--Occupation, 1939-1945.
Prisoners of war--Poland.
Prisoners of war--Soviet Union.
World War, 1939-1945--Campaigns--Poland.
World War, 1939-1945--Prisoners and prisons, Russian.
Harvard subject headings:
Katyn Massacre, Katynʹ, Russia, 1940.
Prisoners of war--Poland
Prisoners of war--Soviet Union.
World War, 1939-1945--Deportations from Poland.
World War, 1939-1945--Prisoners and prisons, Soviet.
Princeton subject headings:
Poland--History--Occupation, 1939-1945.
Prisoners of war--Poland.
Prisoners of war--Soviet Union.
World War, 1939-1945--Campaigns--Poland.
World War, 1939-1945--Prisoners and prisons, Soviet.