Henry David Thoreau, Barry Andrews (2005). “True Harvest: Readings from Henry David Thoreau for Every Day of the Year”, p.167, Unitarian Universalist Association of Congregations
Mary McLeod Bethune, Audrey Thomas McCluskey, Elaine M. Smith (2001). “Mary McLeod Bethune: Building a Better World : Essays and Selected Documents”, p.61, Indiana University Press