David McCullough (2011). “David McCullough American Presidents E-Book Box Set: John Adams, Mornings on Horseback, Truman, The Course of Human Events”, p.306, Simon and Schuster
David McCullough (2011). “David McCullough Library E-book Box Set: 1776, Brave Companions, The Great Bridge, John Adams, The Johnstown Flood, Mornings on Horseback, Path Between the Seas, Truman, The Course of Human Events”, p.24, Simon and Schuster
David McCullough (2011). “David McCullough American History E-book Box Set: John Adams, 1776, Truman, The Course of Human Events”, p.341, Simon and Schuster
David McCullough (2011). “David McCullough Library E-book Box Set: 1776, Brave Companions, The Great Bridge, John Adams, The Johnstown Flood, Mornings on Horseback, Path Between the Seas, Truman, The Course of Human Events”, p.1000, Simon and Schuster
David McCullough (2011). “David McCullough American History E-book Box Set: John Adams, 1776, Truman, The Course of Human Events”, p.541, Simon and Schuster
"Face the Nation April 16, 2017 transcript: McCullough, Chiefs of Staff and a Look at Faith in America". "Face the Nation" with John Dickerson, www.cbsnews.com. April 16, 2017.
David McCullough (2011). “David McCullough Great Moments in History E-book Box Set: 1776, The Johnstown Flood, Path Between the Seas, The Great Bridge, The Course of Human Events”, p.101, Simon and Schuster