Citing Sources

Citing your sources is an essential part of academic writing. It fulfills several key purposes:

• Gives credit to original authors for their ideas, words, or research
• Supports your arguments with credible, verifiable evidence
• Allows readers to identify and find your sources
• Demonstrates academic honesty and helps avoid plagiarism

Failure to cite sources properly may lead to academic penalties including accusations of plagiarism.

You must cite a source whenever you:

• Use direct quotations, regardless of length
• Paraphrase or summarize another person’s ideas
• Mention theories, concepts, or research that originated elsewhere
• Refer to data or statistics that you didn’t collect yourself
• Use visuals such as photos, artwork, or graphs
• Incorporate your own previous work

You do not need to cite:

• Your own original ideas or thoughts
• Your own data and experiments
• Common knowledge, such as widely known facts or easily observable truths (Example: “The Earth revolves around the sun.”)

If you're unsure whether something is common knowledge, cite it to be safe.

Citations must appear in two places:

• In-text citation: Brief information (e.g., author and date) placed within the paragraph or slide where the source is used.
• References list / Works Cited / Bibliography: A complete list of all sources cited in your work, located at the end of the paper or presentation.

The format of both in-text and full citations depends on the citation style used.

Citations should be provided for materials or sources such as:

• Books and book chapters
• Journal, newspaper, or magazine articles
• Dissertations and theses
• Web pages or online content
• Social media posts
• Films, interviews, podcasts, and other media
• Datasets, maps, images, graphs
• Software and code
• Conference papers and presentations
• Government documents
• Court cases, statutes, laws
• Unpublished / archival materials

You need to provide enough information for your reader to easily find your sources. Citation details vary by source type but generally include:

For all sources:

• Author(s) or editor(s)
• Title of the work or article
• Title of the publication (book, journal, website)
• Year of publication

Additional details may include:

• Publisher and place of publication (for books)
• Volume and issue (for journals)
• Page numbers
• URL or DOI (for online sources) - see also What Is a DOI?

Always consult your instructor to confirm which style and edition to use.

The appropriate citation style depends on:

• What style is most used in the academic discipline for which you are writing
• Your instructor’s preferences
• The style guide used by a department, publisher, or journal

There are many different kinds of style guides, but three of the most commonly used are:

• Publication Manual of the American Psychological Association (APA Style)
• The Chicago Manual of Style (Chicago Style)
• MLA Handbook for Writers of Research Papers (MLA Style)

There are also styles created by scholarly or professional associations for specific fields — such as the American Sociological Association or the American Chemical Society or the Associated Press — with publication guidelines especially adapted to their particular disciplines.

See the tabs on the left to explore more about each of these different styles.

Just need to create a quick bibliography? Many library databases (including the library catalog) include a “Cite” option to create a citation for sources you locate in different styles.

Although citation generators are useful for saving time and gathering information quickly, they are not 100% accurate. Formatting errors occur often, so always double-check automatically generated citations using the appropriate style guide.

Common citation generator errors:

• Incorrect capitalization
• Missing punctuation
• Incomplete author or date information
• Formatting inconsistencies (italics, quotation marks, indents, etc.)

Here are some best practices to keep in mind:

• Start keeping track of sources early in your research process.
• Stay consistent with your chosen citation style.
• Consult style guides and citation manuals when unsure.
• When in doubt, it is better to overcite than undercite.
• Ask a librarian, instructor, or writing center consultant if you need help.