David Brainerd (1822). “Memoirs of the Rev. David Brainerd: Missionary to the Indians on the Borders of New-York, New-Jersey, and Pennsylvania: Chiefly Taken from His Own Diary”, p.125
Speech at Amherst College, Amherst, Massachusetts, on October 26, 1963. "Public Papers of the Presidents of the United States: John F. Kennedy", p. 817, 1963.