Desmond Tutu, John Webster (1982). “Bishop Desmond Tutu, the voice of one crying in the wilderness: a collection of his recent statements in the struggle for justice in South Africa”
"The 100 best nonfiction books: No 68 - Narrative of the Life of Frederick Douglass, an American Slave by Frederick Douglass (1845)" by Robert McCrum, www.theguardian.com. May 22, 2017.
Henry Ward Beecher (1887). “Beecher : Christian Philosopher, Pulpit Orator, Patriot and Philantropist: A Volume of Representative Selections from the Sermons, Lectures, Prayers, and Letters of Henry Ward Beecher”