Wallace D. Wattles (2015). “Wallace D. Wattles Ultimate Collection – 10 Books in One Volume: The Science of Getting Rich, The Science of Being Well, The Science of Being Great, How to Get What You Want and more: From one of the New Thought pioneers, author of Making of the Man Who Can or How to Promote Yourself and New Science of Living and Healing or Health Through New Thought and Fasting”, p.208, e-artnow
Immanuel Kant (1900). “Kant's cosmogony as in his essay on the retardation of the rotation of the earth and his Natural history and theory of the heavens: With introduction, appendices, and a portrait of Thomas Wright of Durham”