Stephen R. Covey (2015). “The Stephen R. Covey Interactive Reader - 4 Books in 1: The 7 Habits of Highly Effective People, First Things First, and the Best of the Most Renowned Leadership Teacher of our Time”, p.24, Mango Media Inc.
William Penn (1830). “The Sandy Foundation Shaken; Or, Those ... Doctrines of One God Subsisting in Three Distinct and Separate Persons, the Impossibility of God's Pardoning Sinners Without a Plenary Satisfaction, the Justification of Impure Persons by an Imputative Righteousness, Refuted from the Authority of Scripture Testimonies and Right Reason, Etc”, p.6