Fisher, Chris.A Brief History of Unitarian Christianity (неопр.). The 19th Century. American Unitarian Conference (1 сентября 2004). — «Many churches that were Congregationalist split off and became Unitarian. In 1825, the movement grew large enough that an organization, the American Unitarian Association, was formed». Дата обращения: 24 сентября 2011. Архивировано 27 сентября 2011 года.
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Stone, Darwell. (1903). Outline of Christian Dogma. New York: Longmans, Green & Co. p. 341.
Fisher, Chris.A Brief History of Unitarian Christianity (неопр.). The 19th Century. American Unitarian Conference (1 сентября 2004). — «Many churches that were Congregationalist split off and became Unitarian. In 1825, the movement grew large enough that an organization, the American Unitarian Association, was formed». Дата обращения: 24 сентября 2011. Архивировано 27 сентября 2011 года.
