Henry David Thoreau, Barry Andrews (2005). “True Harvest: Readings from Henry David Thoreau for Every Day of the Year”, p.83, Unitarian Universalist Association of Congregations
Socrates, Plato, Aristotle (1967). “Wit and Wisdom of Socrates, Plato, Aristotle: Being a Treasury of Thousands of Glorious, Inspiring and Imperishable Thoughts, Views and Observations of the Three Great Greek Philosophers, Classified Under about Four Hundred Subjects for Comparative Study”
Samuel Richardson (1820). “Clarissa, Or, The History of a Young Lady: Comprehending the Most Important Concerns of Private Life : and Particularly Shewing the Distresses that May Attend the Misconduct Both of Parents and Children, in Relation to Marriage”, p.255