Columbia subject headings:
Harvard subject headings:
Communists--Germany--Correspondence.
Dutschke, Rudi, 1940-1979--Correspondence.
Germany--Politics and government--1945-1990.
Zahl, Peter-Paul, 1944-2011--Correspondence.
Princeton subject headings:
Dutschke, Rudi, 1940-1979--Correspondence.
Zahl, Peter-Paul, 1944-2011--Correspondence.