Columbia subject headings:
Nixon, Richard M. (Richard Milhous), 1913-1994--Impeachment.
Nixon, Richard M. (Richard Milhous), 1913-1994--Resignation.
Harvard subject headings:
Biographies.
Nixon, Richard M. (Richard Milhous), 1913-1994--Impeachment.
Nixon, Richard M. (Richard Milhous), 1913-1994--Resignation from office.
Princeton subject headings:
Nixon, Richard M. (Richard Milhous), 1913-1994.