Albert Einstein (2013). “Einstein on Politics: His Private Thoughts and Public Stands on Nationalism, Zionism, War, Peace, and the Bomb”, p.228, Princeton University Press
"Mark Burnett Started His Career Jumping Out Of Airplanes And Transporting Prisoners On Ships" by Stephen Chao, www.businessinsider.com. April 21, 2011.
Karl Marx, Friedrich Engels (2014). “The Communist Manifesto: with selections from The Eighteenth Brumaire of Louis Bonaparte and Capital by Karl Marx”, p.9, John Wiley & Sons