Kangaroo, Kangaroo! Thou Spirit of Australia, That redeems from utter failure, From perfect desolation, And warrants the creation Of this fifth part of the Earth.

-Field, Barron
  First Fruits of  Australian Poetry,'The Kangaroo'.

Come forth, Lazarus! And he came fifth and lost the job.

-Joyce,James Augustine Aloysius
  Ulysses.

One fifth of the people are against everything all the time.

-Kennedy, Robert F(rancis)
  In the Observer, May.

La quinta columna. The fifth column.

-Mola, Emilio
  Speech, Oct. Of the rebel sympathizers within Madrid who would help the four columns of nationalist rebels besieging it. Quoted in Hugh Thomas TheSpanish Civil War (1961), ch.4, p.317.

I don't give a shit what happens. I want you all to stonewall†plead the Fifth Amendment, cover-up, or anything else. If that will save it, save the plan.

-Nixon, Richard M(ilhous)
  From the White House tapes relating to the Watergate scandal, recorded Mar.