William Shakespeare (1851). “Dictionary of Shakespearian quotations: Exhibiting the most forcible passages illustrative of the various passions, affections and emotions of the human mind”, p.158
"Mathias Müller von Blumencron, Gregor Peter Schmitz and Gabor Steingart". Interview with Mathias Müller von Blumencron, Gregor Peter Schmitz and Gabor Steingart, www.spiegel.de. November 24, 2008.
Richard Whately (1872). “Elements of Rhetoric: Comprising an Analysis of the Laws of Moral Evidence and of Persuasion, with Rules for Argumentative Composition and Elocution”, p.29
George Washington (1840). “The Writings of George Washington: Being His Correspondence, Addresses, Messages, and Other Papers, Official and Private”, p.396