Basic Citation Styles

Understanding the citation format to use

Acknowledging your sources is crucial to doing honest academic work. That means citing them properly, using one of several styles. The one you choose depends on your fields, your professor’s advice if you are a student, and your own preferences.

There are three major citation styles:

  • Chicago (or Turabian), used in many fields
  • MLA, used in the humanities
  • APA, used in social sciences, education, and business

Several sciences have also developed their own distinctive styles:

  • CSE for the biological sciences
  • AMA for the biomedical sciences, medicine, nursing, and dentistry
  • ACS for chemistry
  • AIP for physics, plus other styles for astrophysics and astronomy
  • AMS for mathematics and computer sciences
  • IEEE and ASCE for engineering.

Compare these bibliographic citations for an article of Charles Lipson, the author of this text:

  • Lipson. Charles. “Why Are Some Internaltional Agreements Informal?” International Organization 45 (Autumn 1991): 495–538.
  • Lipson, C. (1991). Why are some international agreements informal? International Organization, 45, 495–538.
  • Lipson, C. Int. Org. 1991, 45, 495.

Despite their differences, all these citation styles have the same basic goals:

  1. to identify and credit the sources you use; and
  2. to give readers specific information so they can access these sources themselves, if they wish.

How these citations will ultimately look depends on which style you use. Chicago notes are either complete citations or shortened versions plus a complete descriptions in the bibliography or in a previous note. Their name comes from their original source, The Chicago Manual of Style, published by the University of Chicago Press Opens in new window. This format is sometimes called Turabian after a popular book based on that style, Kate Turabian’s A Manual for Writers of Research Papers, Theses, and Dissertations.

APA stands for the American Psychological Association Opens in new window, which uses this style in its professional journals.

MLA stands for the Modern Language Association Opens in new window.

Both styles have been adopted well beyond their original fields. APA is widely used in the social sciences, MLA in the humanities. Chicago citations are widely used in both.

MLA, APA, and the science citation styles were developed to provide alternative ways of referencing materials. They use in-text citations such as (Stewart 154) or (Stewart, 2004) with full information provided only in a reference list at the end. Because these in-text citations are brief, they require a full bibliography.

If you use complete-citation notes, you might not need a bibliography at all since the first note for each item includes all the necessary data. If you use the shortened form, though, you definitely need a bibliography since the notes skip vital information.

Whether you use complete-citation notes or the shortened version, you can place them either at the bottom of each page or at the end of the document. Footnotes and endnotes are identical, except for their placement. Footnotes appear on the same page as the citation in the text. Endnotes are bunched together at the end of the paper, article, chapter, or book. Word processors give you an easy choice between the two.

Fortunately, the different styles include a lot of the same information. That means you can write down the same things as you take notes, without worrying about what kind of citations you will ultimately use. You should write down that information as soon as you start taking notes on a new book or article. If you print out or photocopy an article, write all the reference information on the first page. If you do it immediately, you won’t forget. You’ll need it later for citations. (If you’re downloading some of your citations from the web, make sure the information you’re getting for each source is accurate and complete.)

Tip on selecting a citation style  

Check with your teacher in each class to find out what style citations they prefer. Then use that style consistently.

Your department, school, or publisher may prefer one style or even require it, or they might leave it up to you. Check on that as soon as you begin writing papers with citations. Why not do it consistently from the beginning?

Speaking of consistency … it’s important for proper footnoting. Stick with the same abbreviations and capitalizations, and don’t mix styles within a paper. It’s easy to write “Volume” in one footnote, “Vol.” in another, and “vol.” in a third. We all do it, and then we have to correct it. We all abbreviate “chapter” as both “chap.” And “ch.” Just try your best the first time around and then go back and fix the mistakes when you revise. That’s why they invented the search-and-replace function.