Marcus Tullius Cicero (1855). “Cicero's Three books of offices, or moral duties: also his Cato Major, an essay on old age; Lælius, an essay on friendship; Paradoxes; Scipio's dream; and Letter to Quintus on the duties of a magistrate”, p.203
Frances Ellen Watkins Harper, Frances Smith Foster (1990). “A Brighter Coming Day: A Frances Ellen Watkins Harper Reader”, p.104, Feminist Press at CUNY
François duc de La Rochefoucauld, Stanisław I Leszczyński (King of Poland) (1851). “Moral Reflections, Sentences and Maxims of Francis, Duc de la Rochefoucauld”, p.168