"'Der Witz und seine Beziehung zum Unbewussten' ('Jokes and Their Relation to the Unconscious')". Book by Sigmund Freud, as translated by James Strache, p. 101, 1960.
Edward Gibbon (2016). “EDWARD GIBBON Premium Collection: Historiographical Works, Memoirs & Letters: Including "The History of the Decline and Fall of the Roman Empire”, p.731, e-artnow
"The History of Freedom in Antiquity". Lord Acton's opening statement of his speech on February 28, 1877; later quoted in "The History of Freedom and Other Essays" edited by John Neville Figgis and Reginald Vere Laurence, 1907.