Columbia subject headings:
Bancroft, Mary.
Espionage, American--Switzerland.
Hitler, Adolf, 1889-1945--Assassination attempts.
Spies--Switzerland--Biography.
Spies--United States--Biography.
World War, 1939-1945--Secret service--United States.
Harvard subject headings:
Bancroft, Mary.
Espionage, American--Switzerland.
Hitler, Adolf, 1889-1945--Assassination attempt, 1944 (July 20)
Spies--Switzerland--Biography.
Spies--United States--Biography.
World War, 1939-1945--Secret service--United States.
Princeton subject headings:
Bancroft, Mary.
Espionage, American--Switzerland.
Hitler, Adolf, 1889-1945--Assassination attempts.
Spies--Switzerland--Biography.
Spies--United States--Biography.
World War, 1939-1945--Secret service--United States.