Woodrow Wilson, Ray Stannard Baker, Howard Seavoy Leach (1925). “The Public Papers of Woodrow Wilson: College and state; educational literary and political papers (1875-1913)”
Alister E. McGrath (2007). “Christianity's Dangerous Idea: The Protestant Revolution : a History from the Sixteenth Century to the Twenty-first”, SPCK Publishing
John Adams' letter to Benjamin Rush (December 21, 1809), as quoted in "No, Mr. Beck, John Adams Did Not Think Governments Must Be Administered by the Holy Ghost" by Chris Rodda, www.huffingtonpost.com. June 16, 2010.