Citing sources in academic writing

Citing sources is an important part of academic writing. Whenever you use information or ideas from a source (such as a book, article, or web page), you have to include a citation that gives credit to the original author.

There are many different citation styles with different rules for formatting citations. The most common citation styles are APA and MLA.

The free Scribbr Citation Generator is the quickest way to cite sources in these styles. Simply enter the URL, DOI or title, and we’ll find the necessary details.

When do you need to cite sources?

Citations are required in all types of academic texts (such as essays, research papers, and dissertations). Every time you draw on ideas, summarize information, mention arguments, or give examples that you found in a source, you need to cite it.

To refer to a source, you may quote or paraphrase the original text:

Whether you quote or paraphrase, you must always include a citation in order to avoid plagiarism. Citing also allows your reader to find the original source for themselves, which makes your writing more credible.

As well as citing scholarly sources like books and journal articles, don’t forget to cite any other sources that you use for ideas, examples, or evidence. That includes things like websites, YouTube videos, dictionaries, lectures, and social media posts.

Which citation style should you use?

Many university departments and academic journals require a specific citation style, so first check the guidelines. If no citation style is specified, you need to choose one and use it consistently throughout your paper.

The best choice depends on your field and discipline. APA is the most common style in the social sciences, while MLA is the most common style in the humanities. Other disciplines, like medicine or engineering, often have their own specific styles.

You can check with your instructor or read other papers in your field to see what style they use.

In-text citations and full references

A source citation always includes two main components:

  • A brief in-text citation next to the relevant information.
  • A full reference containing all the information required to find the original source.

Use the interactive tool to see examples of references and in-text citations in APA and MLA.

In-text citations

In-text citations often appear in parentheses, specifying the author’s last name and sometimes (depending on the citation style) a year or page number. Some styles cite using footnotes, endnotes, or bracketed numbers that match reference entries.

Each citation style also has specific rules about citing:

  • sources with multiple authors
  • sources that don’t specify an author
  • sources where the publication date is unknown
  • sources without page numbers
  • multiple sources by the same author

You can find full details of these rules in our style-specific guides to in-text citations.

APA in-text citationsMLA in-text citationsChicago in-text citations

Full references

References are usually listed at the end of the paper on a page called References, Works Cited, or Bibliography.

Full references always include the author, title, and publication date of the source. They also include other information that helps identify the source.

The exact format of a reference depends on the type of source. For example, a book reference includes the publisher and sometimes the edition, while a journal article reference includes volume and issue numbers and the page range where the article appears. See examples of references for common source types below.

Book | Journal article | Website | Newspaper article | Wikipedia | YouTube video | Interview | LectureImage

Using a citation generator

Because each style has many small differences regarding things like italicization, capitalization, and punctuation, it can be difficult to get every detail right. The easiest option is to use a citation generator.

You can use a URL or DOI or input the source details manually, and the generator will automatically produce an in-text citation and reference entry in the correct format. You can save your reference list as you go and download it when you’re done.

Scribbr’s Citation Generators are 100% free, with no ads and no registration required.

APA Citation Generator MLA Citation Generator

Checking your citations

If you lack confidence citing sources, there are automated tools and services that can help you check if you’ve done it correctly. A plagiarism checker makes sure you’ve included citations where they’re needed, while a citation checker makes sure you’ve formatted your citations correctly.

Plagiarism checkers

Universities use plagiarism checking software to scan your paper and identify any similarities to other texts.

When you’re dealing with a lot of sources, it’s easy to make mistakes that could constitute plagiarism—for example, by accidentally forgetting to add a citation after a quote, or paraphrasing a source in a way that’s too close to the original text.

You can avoid this by using a plagiarism checker yourself before you submit the paper. Based on the results, you can add missing citations and rephrase your text where necessary.

There are many free and paid plagiarism checkers available online, so we created a detailed comparison of the options in terms of accuracy and safety.

Citation checkers

Scribbr’s Citation Checker is a unique tool that detects stylistic errors and inconsistencies in your in-text citations. It also suggests a correction for every mistake. Currently available for APA Style, this is the fastest and easiest way to make sure you’ve formatted your citations correctly.

If you need extra help with your reference list, we also offer a citation editing service. Our experts cross-check your in-text citations and reference entries, make sure you’ve included the correct information for each source, and improve the formatting of your reference page.

APA Citation Checker Citation Editing Service

Frequently asked questions about citing sources

When do I need to cite sources?

At college level, you must properly cite your sources in all essays, research papers, and other academic texts (except exams and in-class exercises).

Add a citation whenever you quote, paraphrase, or summarize information or ideas from a source. You should also give full source details in a bibliography or reference list at the end of your text.

The exact format of your citations depends on which citation style you are instructed to use. The most common styles are APA, MLA, and Chicago.

What are the main elements of a book citation?

The main elements included in all book citations across APA, MLA, and Chicago style are the author, the title, the year of publication, and the name of the publisher. A page number is also included in in-text citations to highlight the specific passage cited.

In Chicago style and in the 6th edition of APA Style, the location of the publisher is also included, e.g. London: Penguin.

What are the main elements of a journal article citation?

The elements included in journal article citations across APA, MLA, and Chicago style are the name(s) of the author(s), the title of the article, the year of publication, the name of the journal, the volume and issue numbers, the page range of the article, and, when accessed online, the DOI or URL.

In MLA and Chicago style, you also include the specific month or season of publication alongside the year, when this information is available.

What are the main elements of a website citation?

The main elements included in website citations across APA, MLA, and Chicago style are the author, the date of publication, the page title, the website name, and the URL. The information is presented differently in each style.

When should I use “et al.” in citations?

The abbreviationet al.” (Latin for “and others”) is used to shorten citations of sources with multiple authors.

In APA Style, “et al.” is used in in-text citations of sources with 3+ authors, e.g. (Smith et al., 2019). It is not used in reference entries.

In MLA style, use “et al.” for 3+ authors in in-text citations and Works Cited entries.

In Chicago style, use “et al.” for 4+ authors in an in-text citation, and for 10+ authors in a bibliography entry.

Which citation software does Scribbr use?

The Scribbr Citation Generator is developed using the open-source Citation Style Language (CSL) project. It’s the same technology used by dozens of other popular citation tools, including Mendeley and Zotero.

You can find all the citation styles and locales used in the Scribbr Citation Generator in our publicly accessible repository on Github.

Who uses APA style?

APA format is widely used by professionals, researchers, and students in the social and behavioral sciences, including fields like education, psychology, and business.

Be sure to check the guidelines of your university or the journal you want to be published in to double-check which style you should be using.

Who uses MLA style?

MLA Style is the second most used citation style (after APA). It is mainly used by students and researchers in humanities fields such as literature, languages, and philosophy.

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