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Citations and Style Guides

Information on plagiarism and citations, including APA and MLA.

Plagiarism Explained

Types of plagiarism


Mixing words or ideas from an unacknowledged source in with your own words or ideas.

  • Mixing together uncited words and ideas from several sources into a single work.
  • Mixing together properly cited uses of a source with uncited uses.

Direct Plagiarism

  • A phrase or passage that is copied word for word, but not quoted.


  • Rephrasing another person’s work and inserting into your own work without acknowledging the original source.

Insufficient Acknowledgement

  • Half crediting source; whereby you acknowledge the author’s work the first time, but continue to use the author’s words without giving additional attribution.

Common Knowledge


Anything you state as a fact must be supported by literature or other forms of statistical data.  However, there are certain facts that are so well known, there is no place to cite them.  Be careful with common knowledge, however.  As the APA blog demonstrates, even the most obvious fact may not be accurate.

Rule of thumb: if you can find the fact without citation in at least five reputable sources, it is probably common knowledge.

Common knowledge:

  • The sky is blue
  • Christmas is held annually on December 25th
  • The American Civil War was fought from 1861 to 1865
  • The molecular structure of water (H20)

Not common knowledge:

  • Any published theory or viewpoint, no matter how many times it is mentioned in the text.  For instance, Maslow's Heirarchy.
  • Statistics

When in doubt, cite it!

Courtesy Colorado Technical University.