John Milton (1824). “The Poetical Works of John Milton: With Notes of Various Authors, Principally from the Edition of Thomas Newton, Charles Dunster, and Thomas Warton, to which is Prefixed, Newton's Life of Milton”, p.154
"James Hansen on the Tar Sands Pipeline Protest, the Obama Administration and Intergenerational Justice". Interview with Jerry Cope, www.huffingtonpost.com. August 21, 2011.
Pope Benedict XVI, Peter Seewald (2002). “God and the World: Believing and Living in Our Time : a Conversation with Peter Seewald”, p.46, Ignatius Press