How to Cite Sources in APA, MLA & Chicago
Quick Answer
APA uses author-date in-text citations and a References page. MLA uses author-page and a Works Cited page. Chicago offers footnotes (notes-bibliography) or author-date. Each format has specific rules for ordering author names, titles, dates, and URLs.
Which Citation Style Should You Use?
Your professor or institution determines the citation style. There isn't a “best” one — each was designed for a specific academic discipline with different priorities.
| Style | Used In | Key Feature | Current Edition |
|---|---|---|---|
| APA | Psychology, Education, Social Sciences, Nursing | Emphasizes publication date | 7th Edition (2019) |
| MLA | English, Literature, Languages, Arts | Emphasizes author name | 9th Edition (2021) |
| Chicago | History, Business, Fine Arts | Two systems (notes or author-date) | 17th Edition (2017) |
If your assignment doesn't specify, ask. Using the wrong style is a common way to lose points on otherwise solid papers.
APA 7th Edition: The Essentials
Reference List Format
APA references follow a consistent pattern: Author. (Date). Title. Source. The details change depending on the source type, but the four-part structure stays the same.
Book: Smith, J. D. (2024). The art of studying. Academic Press.
Journal article: Johnson, A. B., & Lee, C. (2025). Student performance metrics in online learning. Journal of Education Research, 42(3), 112–128. https://doi.org/10.1234/jer.2025.42.3.112
Website: Williams, R. (2025, February 10). Study habits that actually work. Education Weekly. https://example.com/study-habits
In-Text Citations
APA uses author-date: (Smith, 2024). For direct quotes, add the page number: (Smith, 2024, p. 45). For two authors: (Johnson & Lee, 2025). For three or more: (Smith et al., 2024).
MLA 9th Edition: The Essentials
Works Cited Format
MLA uses a “core elements” approach: Author. Title. Container, Contributors, Version, Number, Publisher, Date, Location. Not every source has all elements — include what's available.
Book: Smith, John D. The Art of Studying. Academic Press, 2024.
Journal article: Johnson, Anna B., and Chris Lee. “Student Performance Metrics in Online Learning.” Journal of Education Research, vol. 42, no. 3, 2025, pp. 112–128.
Website: Williams, Rachel. “Study Habits That Actually Work.” Education Weekly, 10 Feb. 2025, example.com/study-habits.
In-Text Citations
MLA uses author-page: (Smith 45). No comma between author and page number. For no page numbers (common with websites), just the author: (Williams). For two authors: (Johnson and Lee 115).
Chicago Style: Notes-Bibliography
Chicago's notes-bibliography system uses footnotes (or endnotes) instead of parenthetical citations. The first time you cite a source, the footnote includes full publication details. Subsequent references use a shortened form.
First footnote: 1. John D. Smith, The Art of Studying (New York: Academic Press, 2024), 45.
Subsequent: 2. Smith, Art of Studying, 78.
The bibliography at the end lists sources alphabetically by author's last name, similar to MLA but with different punctuation and formatting.
Common Citation Mistakes
Missing the hanging indent. All three styles use a hanging indent on the reference/works cited page. The first line is flush left; subsequent lines are indented 0.5 inches. This is a formatting detail professors notice immediately.
Incorrect capitalization. APA uses sentence case for article titles (only first word and proper nouns capitalized). MLA and Chicago use title case (capitalize major words). Getting this wrong flags your citation as sloppy.
Forgetting the DOI.In APA, if a journal article has a DOI, you must include it. Format: https://doi.org/10.xxxx/xxxxx. Not “DOI: 10.xxxx” — the full URL format is required in APA 7th edition.
Citing the wrong date for websites.Use the publication date (when the content was created), not the date you accessed it. APA 7th edition removed the “Retrieved from” wording for most web sources. Only include a retrieval date if the content is likely to change (like a wiki page).
Mixing styles. Some students use APA for some citations and MLA for others in the same paper. Pick one and stick with it throughout.
When to Cite (and When Not To)
Cite any time you use someone else's ideas, words, data, or arguments. This includes direct quotes, paraphrases, statistics, images, and data from studies. You don't need to cite common knowledge (“the earth revolves around the sun”) or your own original analysis.
When in doubt, cite. Overcitation is a minor style issue. Undercitation is plagiarism. The risk profile is completely asymmetric.
Use the citation generator to format your sources correctly in seconds. Paste in a URL, book ISBN, or article DOI and get a properly formatted citation in your chosen style.