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.250
"Of Old Age". Book by Marcus Tullius Cicero, book 5, section 15, reported in "Cicero on the Art of Growing Old", book by Herbert N. Couch (1959), p. 21,