Columbia subject headings:
Catholic Church--Prussia, East (Poland and Russia)--History--20th century.
Catholic Church. Diocese of Warmia (Poland)
Catholics--Prussia, East (Poland and Russia)--History--20th century.
Ermland (Ecclesiastical principality)
Germany--Church history--1945-
Kaller, Maximilian, 1880-1947--Correspondence.
Persecution--Prussia, East (Poland and Russia)--History--20th century.
Prussia, East (Poland and Russia)--Church history--20th century.
Religious refugees--Prussia, East (Poland and Russia)--History--20th century.
Harvard subject headings:
Catholic Church--Ermland (Ecclesiastical principality)--History.
Catholic Church. Diocese of Warmia (Poland)--History--20th century.
Catholics--Prussia, East (Poland and Russia)--History--20th century.
Germany--Church history--1945-
Persecution--Prussia, East (Poland and Russia)--History--20th century.
Religious refugees--Poland--Warmia--Social conditions--20th century.
Warmia (Poland)--History--20th century.
Princeton subject headings: