Citing Your Sources

Why Cite?

Citation is the practice of providing information about the sources you have used in your writing. This allows readers to trace ideas back to their original sources and gives credit to the original author.

Citation acknowledges any source that has directly influenced your language, ideas, or arguments. You should cite not only what you quote, but also what you paraphrase.

If you don't cite, you may be guilty of plagiarism.

Elements of a Citation

While the exact parts of a citation vary from one source type to the next, the most common elements address the questions who, what, when, and where.


This is the name of the person (author, composer, artist) who is responsible for the work being cited. It may be an institution rather than an individual, as in many government documents.


The title of the work


The date of the item being cited. Usually, only the year is required, but if you have more specific information, you can include that as well.


Where can someone who is interested in this source find it? This information may include one or more of the following:

  • Publication title (with volume, number, and page numbers)
  • URL - for example,
  • DOI (digital object identifier) - for example, 10.1016/j.nut.2015.05.021

Reading a Citation

Sample citation in APA style with parts labeled
Sample Citation in APA Style

Reference Lists & In-Text Citations

Correctly citing a work is a two-part process.

The Reference List

This lists the complete details of every item you cite. It is located at the end of your paper.

A full APA-style citation for a scientific paper might look like this:

Pont, C., Wagner, S., Kremer, A., Orlando, L., Plomion, C., & Salse, J. (2019). Paleogenomics: reconstruction of plant evolutionary trajectories from modern and ancient DNA. Genome Biology, 20(1), 29–17.

In-Text Citations

These occur within the body of your paper, either as parenthetical notes or as footnotes. These give a shorter form of the citation. Interested readers can refer to your reference list for complete details.

The in-text citation for the paper listed above might look like this:

DNA sequences from subfossil remains can inform our understanding of modern plant genome organization (Pont et al., 2019).

Citation Styles

Many different organizations and publications have developed rules for how sources should be cited. For undergraduate work, APA, MLA, and Chicago are the most used. Make sure that you follow the rules of the style preferred by your instructor. If your instructor just says, "be consistent," pick one of the common styles to use. For information on specific styles, see our Citation Styles page.

Citation Managers

Writing bibliographies can be tedious and time-consuming. Luckily, there are free tools that will create them for you. Such tools will let you collect a set of sources and then drop them into your paper as you type. We recommend Zotero (our guide).