Anthony Kenny describes Anselm’s theory of the Atonement, from Medieval History: A New History of Western Philosophy, Volume 2. (Oxford: Clarendon Press, 2005), page 43

Kenneth Latourettes explanation of Anselm’s theory of the Atonement, from A History of Christianity (NY: Harper & Brothers, 1953, page 501

Robert P. Lightner charts the major theories of the Atonement, from Sin, The Savior, and Salvation (Nashville: Thomas Nelson, 1991) page 105

Everett Ferguson on Anselms theory of the Atonement, from Church History: Volume 1, From Christ to Pre-Reformation (Grand Rapids: Zondervan, 2005), pages 433-435