Wright, Conrad. Three Prophets of Religious Liberalism: Channing, Emerson, Parker (Boston: Skinner House Books, 1994)

Howe, Charles A., "The Humiliati," in the Dictionary of Unitarian and Universalist Biography

Murray, John and Judith Sargent Murray, The Life of Rev. John Murray: Preacher of Universal Salvation (Boston: Universalist Publishing House, 1869)

Andrews, Barry M. Emerson as Spiritual Guide: A Companion to Emerson's Essays for Personal Reflection and Group Discussion (Boston: Skinner House, 2003), Thoreau as Spiritual Guide: A Companion to Walden for Personal Reflection and Group Discussion (Boston: Skinner House, 2000), and The Spirit Leads: Margaret Fuller in Her Own Words (Boston: Skinner House, 2010).