Chicago: Aristotle, "Chapter 21 (15)," On Youth and Old Age, On Life and Death, On Breathing, trans. G. R. T. Ross Original Sources, accessed April 23, 2024, http://www.originalsources.com/Document.aspx?DocID=GNVQ79NMW8LLS8U.
MLA: Aristotle. "Chapter 21 (15)." On Youth and Old Age, On Life and Death, On Breathing, translted by G. R. T. Ross, Original Sources. 23 Apr. 2024. http://www.originalsources.com/Document.aspx?DocID=GNVQ79NMW8LLS8U.
Harvard: Aristotle, 'Chapter 21 (15)' in On Youth and Old Age, On Life and Death, On Breathing, trans. . Original Sources, retrieved 23 April 2024, from http://www.originalsources.com/Document.aspx?DocID=GNVQ79NMW8LLS8U.