Columbia subject headings:
Harvard subject headings:
Espionage, German
Germany--Politics and government--1945-1990--Sources.
Intelligence service--Germany (East)--History--Sources.
Spies--Germany--Correspondence.
Wolf, Markus, 1923-2006--Correspondence.
Princeton subject headings:
Germany (East)--Politics and government.
Germany (East). Ministerium für Staatssicherheit--Biography.
Intelligence service--Germany (East)--Biography.
Spies--Germany (East)--Biography.
Wolf, Markus, 1923-2006--Correspondence.
Wolf, Markus, 1923-2006--Friends and associates--History.
Wolf, Markus, 1923-2006--Genealogy.
Wolf, Markus, 1923-2006.