To reference an essay, you credit every source you use in two places: a short citation in the text right where you use the source, and a full entry in a reference list at the end. The exact format depends on the citation style your instructor requires, usually APA, MLA, Chicago or Harvard. This guide shows how to reference an essay in each style, with the same two sources cited every way, so you can compare the formats side by side and get your citations right the first time.
How to Reference an Essay in 4 Steps
- Find out which style to use. Check the assignment sheet or syllabus. Psychology, education, nursing and most social sciences use APA; literature and languages use MLA; history often uses Chicago; many UK and Australian universities use a version of Harvard.
- Record source details as you research. For every source, save the author, title, date, publisher or journal, volume and issue, page numbers and DOI or URL. Finding these again later is the slowest part of referencing.
- Cite in the text as you write. Add an in-text citation every time you quote, paraphrase or summarize a source, including statistics and specific ideas, not just direct quotations.
- Build the reference list and check it. List every cited source in the format your style requires, then check that every in-text citation matches an entry and every entry is cited at least once.
In-Text Citations vs the Reference List
Every style uses both parts, and they work together. The in-text citation is short and points the reader to the full entry.
| Part | Where it goes | What it contains | What it is called |
|---|---|---|---|
| In-text citation | In the sentence or at the end of it, or in a footnote for Chicago notes | Author and year (APA, Harvard), author and page (MLA), or a note number (Chicago) | Citation, parenthetical citation or note |
| Reference list | On a new page at the end of the essay | Full details for each source, in alphabetical order by author | References (APA, Harvard), Works Cited (MLA), Bibliography (Chicago) |
Throughout the examples below, we cite the same two real sources: a book, Cal Newport’s Deep Work (2016), and a journal article by Pam Mueller and Daniel Oppenheimer on note-taking, published in Psychological Science in 2014.
APA Style (7th Edition) Examples
APA uses the author-date system. Capitalize only the first word of a book or article title (and the first word after a colon), and italicize book titles, journal names and volume numbers. The official APA reference examples cover dozens of other source types.
In-text: (Newport, 2016, p. 3) and (Mueller & Oppenheimer, 2014). In a sentence: Mueller and Oppenheimer (2014) found that…
Reference list:
Mueller, P. A., & Oppenheimer, D. M. (2014). The pen is mightier than the keyboard: Advantages of longhand over laptop note taking. Psychological Science, 25(6), 1159–1168. https://doi.org/10.1177/0956797614524581
Newport, C. (2016). Deep work: Rules for focused success in a distracted world. Grand Central Publishing.
APA requires a page number for direct quotations and encourages one for paraphrases of specific passages. See the APA guide to in-text citations for rules on three or more authors, which use “et al.” from the first citation, and our guide on how to format an APA paper for the page setup.
MLA Style (9th Edition) Examples
MLA uses the author-page system and calls the reference list “Works Cited.” Titles use title case, books and journals are italicized, and article titles go in quotation marks. Entries follow the MLA core elements in a set order: author, title, container, other contributors, version, number, publisher, date and location. The MLA Style Center’s works-cited guidance explains each element.
In-text: (Newport 3) and (Mueller and Oppenheimer 1160). There is no comma between the author and the page number.
Works Cited:
Mueller, Pam A., and Daniel M. Oppenheimer. “The Pen Is Mightier Than the Keyboard: Advantages of Longhand over Laptop Note Taking.” Psychological Science, vol. 25, no. 6, 2014, pp. 1159–68, https://doi.org/10.1177/0956797614524581.
Newport, Cal. Deep Work: Rules for Focused Success in a Distracted World. Grand Central Publishing, 2016.
Purdue OWL’s guide to the MLA Works Cited page covers spacing and hanging indents, and our MLA references guide has more examples, including websites and films.
Chicago Style Examples
Chicago offers two systems. History and the humanities usually use notes and bibliography, with numbered footnotes or endnotes. The sciences sometimes use Chicago’s author-date system, which looks similar to APA. The examples below use notes and bibliography and follow the 18th edition of the Chicago Manual of Style, published in 2024, which no longer requires the city of publication for books. If your course uses the 17th edition, add the city before the publisher, for example (New York: Grand Central Publishing, 2016).
Footnotes:
1. Cal Newport, Deep Work: Rules for Focused Success in a Distracted World (Grand Central Publishing, 2016), 3.
2. Pam A. Mueller and Daniel M. Oppenheimer, “The Pen Is Mightier Than the Keyboard: Advantages of Longhand over Laptop Note Taking,” Psychological Science 25, no. 6 (2014): 1160, https://doi.org/10.1177/0956797614524581.
Bibliography:
Mueller, Pam A., and Daniel M. Oppenheimer. “The Pen Is Mightier Than the Keyboard: Advantages of Longhand over Laptop Note Taking.” Psychological Science 25, no. 6 (2014): 1159–68. https://doi.org/10.1177/0956797614524581.
Newport, Cal. Deep Work: Rules for Focused Success in a Distracted World. Grand Central Publishing, 2016.
Later notes for the same source can use a short form, such as: 3. Newport, Deep Work, 45. The Chicago Manual of Style citation quick guide shows both systems, and our guide to footnotes explains how to insert them in Word and Google Docs.
Harvard Style Examples
Harvard is an author-date style like APA, but there is no single official Harvard manual. Universities publish their own versions, so punctuation and capitalization vary slightly. The examples below follow a widely used format; always check your university’s Harvard guide first.
In-text: (Newport, 2016, p. 3) and (Mueller and Oppenheimer, 2014).
Reference list:
Mueller, P.A. and Oppenheimer, D.M. (2014) ‘The pen is mightier than the keyboard: advantages of longhand over laptop note taking’, Psychological Science, 25(6), pp. 1159–1168. Available at: https://doi.org/10.1177/0956797614524581.
Newport, C. (2016) Deep work: rules for focused success in a distracted world. New York: Grand Central Publishing.
How to Cite Quotes, Paraphrases and Tricky Sources
The rules above cover most citations, but a few situations come up in nearly every essay.
- Direct quotations: put the exact words in quotation marks and include a page number in every style. Long quotations, roughly 40 words or more in APA and more than four lines in MLA, become indented block quotations without quotation marks.
- Paraphrases and summaries: still need a citation, even though the words are your own. The idea belongs to the source. Purdue OWL’s guide to quoting, paraphrasing and summarizing shows how to do each correctly.
- No author: use the organization as the author, such as a government agency. If there is no organization either, start the citation with the title.
- No date: APA uses “n.d.” for no date. MLA simply leaves the date out, and many instructors also ask for the date you accessed a web page.
- Secondary sources: if you read a quotation in one source but it came from another, cite the source you actually read, for example (Smith, 1999, as cited in Jones, 2020) in APA. Better still, find and read the original.
- AI tools: if your instructor allows AI tools, APA, MLA and Chicago have each published guidance on how to cite them. Check your course policy first.
Common Referencing Mistakes
| Mistake | How to fix it |
|---|---|
| Mixing styles, such as APA in-text citations with an MLA Works Cited page | Pick one style and use it for every citation and entry. |
| Citations with no matching reference entry | Check every in-text citation against the list before you submit. |
| Missing page numbers for quotations | Record page numbers when you take notes. |
| Wrong order in the reference list | Alphabetize by the first author’s last name in APA, MLA, Chicago and Harvard. |
| Copying generator output without checking | Citation generators often get capitalization, author names and dates wrong. Always compare the result with the style guide. |
| No hanging indent | Indent the second and later lines of each entry by half an inch. |
Referencing is also your best protection against accidental plagiarism, because it shows exactly which ideas came from which sources. Our guide to understanding and avoiding plagiarism explains the rules, and our explainer on what a bibliography is covers how a bibliography differs from a reference list.
If you have a draft that needs its citations checked or formatted, a writing tutor can help. See our essay writing help, or post your assignment to compare bids from tutors.
How to Format the Reference List Page
The reference list is usually graded on format as well as content, so small layout details matter. These rules apply in APA, MLA, Chicago and most versions of Harvard, with the differences noted.
- Start on a new page after the last page of your essay, with the heading centered: References (APA and Harvard), Works Cited (MLA) or Bibliography (Chicago).
- Use the same font and spacing as the essay. APA and MLA use double spacing throughout, including the reference list. Chicago bibliographies are often single-spaced within entries with a blank line between them; follow your instructor.
- Use a hanging indent: the first line of each entry sits at the margin, and the following lines are indented half an inch.
- Alphabetize by the first author’s last name. Entries with no author are alphabetized by the first significant word of the title, ignoring “A,” “An” and “The.”
- Keep author names in the same order as they appear on the source, and do not shorten the list to the first author in the reference list.
- Include DOIs when they exist. APA and MLA both prefer a DOI written as a full https://doi.org/ link over a database URL.
Using Reference Managers Without Losing Marks
Free reference managers such as Zotero and Mendeley, and the citation tools built into Word and Google Docs, can store your sources and insert citations in the style you choose. They save real time on long papers, especially when you have dozens of sources or need to switch styles.
They are only as accurate as the information you give them, though. Imported records often have titles in the wrong case, missing issue numbers or a website listed as the author. Before you submit, compare a few entries against the official examples for your style, fix the pattern of errors you find, and check the rest. If your course uses an older edition of a style, make sure the tool is set to the same edition, because APA 7 and MLA 9 changed several rules from earlier editions.
A good habit is to add each source to your manager the moment you decide to use it, with the page numbers of any quotations in the notes field. That way the reference list builds itself while you research instead of becoming a separate job at the end.
Frequently Asked Questions
What Is the Difference Between Referencing and Citing?
Citing usually means the short in-text citation you place where you use a source, while referencing often means the full list of sources at the end. In practice, many instructors use the words interchangeably. Every citation style needs both parts: the in-text citation tells the reader which source you used, and the reference entry gives the details needed to find it.
Which Citation Style Should I Use for My Essay?
Use the style your instructor or department requires, which is usually stated in the syllabus or assignment sheet. As a general guide, APA is common in psychology, education, nursing and business, MLA in English and languages, Chicago in history, and Harvard at many UK and Australian universities. If no style is specified, ask, because switching styles later takes time.
Do I Need to Cite Something I Paraphrased?
Yes. A paraphrase restates a source’s idea in your own words, but the idea still belongs to the source, so you must cite it. Only common knowledge, facts that are widely known and easily found in many general sources, can go without a citation. When in doubt, cite the source, because uncited paraphrasing can be treated as plagiarism.
How Do I Reference a Website with No Author?
Use the organization that published the page as the author if there is one, such as a government agency or university. If there is no identifiable author or organization, start the entry with the page title. Include the date of publication if available, or use “n.d.” in APA, and add the URL. Some styles and instructors also ask for the date you accessed the page.
Are Citation Generators Accurate?
They save time but often make mistakes, especially with capitalization, author names, missing page numbers and source types. Treat generator output as a first draft. Compare each entry with the official style guide examples and fix any errors, because instructors grade the final reference list, not the tool that produced it.
How Many References Should an Essay Have?
Follow the assignment’s requirement, which often specifies a minimum number of scholarly sources. Without one, a common guideline for a short college essay is about one source per 250 to 300 words, but quality matters more than quantity. Cite every source you actually use, and do not list sources you did not cite in the text.
