John Bunyan, George Offor (1862). “The Whole Works of John Bunyan: Accurately Reprinted from the Authors Own Editions ; Wth Editorial Prefaces, Notes, and Life of Bunyan”, p.721
Brad Warner (2010). “Zen Wrapped in Karma Dipped in Chocolate: A Trip Through Death, Sex, Divorce, and Spiritual Celebrity in Search of the True Dharma”, p.89, New World Library