Manly P. Hall (2010). “The Secret Teachings of All Ages: An Encyclopedic Outline of Masonic, Hermetic, Qabbalistic and Rosicrucian Symbolical Philosophy”, p.438, Courier Corporation
Henry David Thoreau, Barry Andrews (2005). “True Harvest: Readings from Henry David Thoreau for Every Day of the Year”, p.26, Unitarian Universalist Association of Congregations