Lee Child (2015). “The Essential Jack Reacher, Volume 2, 6-Book Bundle: 61 Hours, Worth Dying For, The Affair, A Wanted Man, Never Go Back, Personal”, p.175, Delacorte Press
John Newton (1847). “One Hundred and Twenty Nine Letters from the Rev. John Newton ... to the Rev. William Bull, of Newport Pagnell: Written During a Period of Thirty-two Years, from 1773 to 1805 ...”, p.5