Joseph Sittler, Steven Bouma-Prediger, Peter W. Bakken (2000). “Evocations of Grace: The Writings of Joseph Sittler on Ecology, Theology, and Ethics”, p.202, Wm. B. Eerdmans Publishing
Charles Haddon Spurgeon (1988). “Spurgeon at His Best: Over 2200 Striking Quotations from the World's Most Exhaustive and Widely-read Sermon Series”, Baker Publishing Group