Richard P. Feynman, Robert B. Leighton, Matthew Sands (2015). “The Feynman Lectures on Physics, Vol. II: The New Millennium Edition: Mainly Electromagnetism and Matter”, p.71, Hachette UK
"A Discourse Addressed to Magistrates and Men in Authority: Occasioned by the Enormous License, and Irreligion of the Times". Book by George Berkeley, 1738.