Robert Barclay, George Keith (1831). “Truth Triumphant Through the Spiritual Warfare, Christian Labours, and Writings of that Able and Faithful Servant of Jesus Christ, Robert Barclay,: To which is Prefixed, an Account of His Life”, p.15
Nathaniel Branden (2011). “How to Raise Your Self-Esteem: The Proven Action-Oriented Approach to Greater Self-Respect and Self-Confidence”, p.28, Bantam