Albert Einstein, Stephen W. Hawking (2007). “A Stubbornly Persistent Illusion: The Essential Scientific Works of Albert Einstein”, p.346, Running Press
Nelson A. Miles (1992). “Personal Recollections and Observations of General Nelson A. Miles, Embracing a Brief View of the Civil War, Or, From New England to the Golden Gate and the Story of His Indian Campaigns with Comments on the Exploration, Development, and Progress of Our Great Western Empire”, p.345, U of Nebraska Press
Francis Quarles (1844). “Enchiridion Institutions, Essays and Maxims, political, moral & divine. Divided into four centuries. By Francis Quarles”, p.39