Theodore Roosevelt (2015). “Theodore Roosevelt on Bravery: Lessons from the Most Courageous Leader of the Twentieth Century”, p.36, Skyhorse Publishing, Inc.
Thomas Boston (1791). “The Distinguishing Characters of True Believers: In Relation To, I. God in Christ, ... XI. Their Entering Into Rest in Christ. ... To which is Prefixed, a Soliloquy on the Art of Man-fishing. Now First Published from the Manuscripts of the Late Reverend and Learned Mr Thomas Boston, ...”, p.44