Propaganda is often classified into three separate genres - White, Grey or Black - depending on the transparency with which it attributes its true authors. White Propaganda is correctly attributed to the sponsor and the source is truthfully identified. Grey Propaganda, on the other hand, is unattributed to the sponsor and conceals the real source of the Propaganda. The objective of Grey Propaganda is to advance viewpoints that are in the interest of the originator but that would be more acceptable to target audiences than official statements. Black Propaganda also camouflages the sponsor's participation. But while Grey Propaganda is unattributed, Black Propaganda is falsely attributed. Black Propaganda is subversive and provocative; it is usually designed to appear to have originated from a hostile source, in order to cause that source embarrassment, to damage its prestige, to undermine its credibility, or to get it to take actions that it might not otherwise.
- Wikipedia, Propaganda: Overview of Propaganda
- Wikipedia, History of Propaganda: History of Propaganda techniques
- Edward Bernays (1982), Propaganda: Publication of a key Propaganda theorist
- William Levinson (1999), An Introduction to Propaganda: Introduction to the concept of Propaganda
- University of Southern California (2006), Two Ways of Looking At Propaganda: A look at some ethical questions surrounding Propaganda
- British Library, Propaganda: Collection of articles on World War 1 Propaganda
- Richard Nelson (1996), A Chronology and Glossary of Propaganda in the United States, pp.232–233
- Paul Linebarger (1954), Psychological Warfare, Combat Forces Press: Washington, DC. p.39.
- Kenneth Osgood (2002), Propaganda, Encyclopedia of American Foreign Policy, accessed 02 April 2015
- William Levinson (1999), An Introduction to Propaganda, Stentorian website, accessed 02 April 2015