Columbia subject headings:
Hyde, H. Montgomery (Harford Montgomery), 1907-1989.
Intelligence officers--Great Britain--Biography.
Intelligence service--Great Britain.
Intelligence service--United States.
Harvard subject headings:
Hyde, H. Montgomery (Harford Montgomery), 1907-
Intelligence officers--Great Britain--Biography.
Intelligence service--Great Britain.
Intelligence service--United States.
Princeton subject headings:
Hyde, H. Montgomery (Harford Montgomery), 1907-1989.
Intelligence officers--Great Britain--Biography.
Intelligence service--Great Britain.
Intelligence service--United States.