Albert Einstein, Stephen W. Hawking (2007). “A Stubbornly Persistent Illusion: The Essential Scientific Works of Albert Einstein”, p.346, Running Press
Albert Einstein (2016). “The Albert Einstein Collection: Essays in Humanism, The Theory of Relativity, and The World As I See It”, p.116, Open Road Media
Robert N. Goldman, Albert Einstein (1997). “Einstein's God: Albert Einstein's Quest as a Scientist and as a Jew to Replace a Forsaken God”, Jason Aronson Incorporated
Albert Einstein, Stephen W. Hawking (2007). “A Stubbornly Persistent Illusion: The Essential Scientific Works of Albert Einstein”, p.402, Running Press