Marie Curie's letter to Eve Curie Labouisse (July 1929), as quoted in Eve Curie Labouisse "Madame Curie: A Biography" translated by Vincent Sheean (p. 341), 1937.
Samuel Johnson, Arthur Murphy (1825). “The Works of Samuel Johnson, LL.D.: Journey to the Hebrides. Tales of the imagination. Prayers and sermons. Index”, p.309