Columbia subject headings:
Czech Republic--Boundaries--Poland.
Espionage, Polish--Czechoslovakia.
Poland--Boundaries--Czech Republic.
Poland--Politics and government--1918-1945.
Silesia, Upper (Poland and Czech Republic)--History--20th century.
Subversive activities--Czechoslovakia.
Harvard subject headings:
Czech Republic--Boundaries--Poland.
Espionage, Polish--Chechoslovakia.
Poland--Boundaries--Czech Republic.
Poland--Politics and government--1918-1945
Silesia, Upper (Poland and Czech Republic)--History--20th century.
Subversive activities--Czechoslovakia.
Princeton subject headings: