Columbia subject headings:
Harvard subject headings:
Buchenwald (Concentration camp)
Friedrich, Leonhard, 1889-1979.
Friedrich, Mary, 1882-1970
Germany--Ethnic relations.
Holocaust, Jewish (1939-1945)--Germany
Jews--Persecutions--Germany.
Quakers--Germany--Biography.
Quakers--Persecutions--Germany.
Righteous Gentiles in the Holocaust--Biography
Princeton subject headings:
Friedrich, Leonhard, 1889-1979.
Friedrich, Mary, 1882-1970.
Germany--History--1933-1945.
Quakers--Germany--20th century--Biography.
Quakers--Persecutions--Germany--20th century.