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How to cite a source within a source

By: Sarah-Jean Watt, Write Site coordinator

Dear Write Site is a new series that equips Athabasca University (AU) learners with tips and tricks to improve their writing—whether it’s for an essay, research paper, or the next great novel. We will feature advice from the Write Site, AU’s academic writing support services, with answers to learner questions.

Dear Write Site,

I am writing a research paper. I found many good ideas in one article, but the ideas have citations, meaning they came from other articles. How can I correctly cite these ideas?

—Citing Tooth and Nail

Dear Citing Tooth and Nail,

When researching, it is common for one article to lead you to another. You can certainly cite the author of the article directly if you are discussing their own ideas, analysis, or interpretation. However, if you are directly discussing only the sources the article itself cited, the best practice is usually to find and use the original sources. And, if you have no choice but to cite one source via another, there is a particular way to do so. Below, you’ll find instructions for APA, MLA, and Chicago.

Note that you may also see original sources referred to as primary sources, and sources that cite and analyze other sources referred to as secondary or indirect sources. The meaning and use of each type of source may be discipline- or context-specific, so check with your instructor.

Benefits of citing the original

To cite the original source directly, first you will have to search for the original article from the library website. If you need help tracking it down, a librarian can support you.

Once you have access to the original source, you can cite it directly. This is beneficial because you may not understand the full context of the material without viewing it in the original. And, there is another advantage to this extra work. By reviewing the original source, you may even find more useful information for your paper.

When you have no other choice

Occasionally you may not be able to cite the original source: for instance, if the original source is “out of print, unavailable, or available only in a language that you do not understand,” as the Concise Guide to APA Style explains.

The MLA Handbook (9th edition) requests that original material be cited whenever possible but acknowledges that there are sometimes cases where it is appropriate to cite original material through an “indirect source.” It gives an example of a speech in which the orator quoted an ancient Greek dramatist. In this case, it may be relevant to quote the cited source as used within the speech.

How to cite a source within a source in APA

In, APA, the typical way to cite one source via another is to include the author and year of the original source in the in-text citation.

(Piaget, 1947, as cited in Fernandes & Bell, 2020).

The information can also be given in whole or in part within your sentence:

Fernandes and Bell (2020) refer to Piaget’s (1947) discussion in The Psychology of Intelligence.


Piaget (1947) once wrote that “intelligence, the most plastic and at the same time the most durable structural equilibrium of behaviour, is essentially a system of living and acting operations” (as cited in Fernandes & Bell, 2020, p. 136).

Your APA references page will only include an entry for the source you are using (Fernandes & Bell, 2020), and not one for the original source.

How to cite a source within a source in MLA

MLA uses a shortened form of the phrase “quoted in” when quoting an indirect source. Place the name of the original author before “qtd. in”, and follow that with the author’s name from the source you are working with:

From the beginning of the novel, the innocent intellect of childhood is conjured: “Lawyers, I suppose, were children once” (Lamb qtd. in Lee 5).

It may be preferable to give the context in which the quote appears. In fact, if your sentence explains that the quoted source is indirect, you can drop “qtd. in” altogether:

Charles Lamb’s reflective words make up the epigraph in To Kill a Mockingbird: “Lawyers, I suppose, were children once” (Lee 5).

Similarly, avoid the use of “qtd. in” when paraphrasing. The paraphrase must instead show that the citation is indirect by naming or otherwise identifying the original source.

Like APA, MLA includes only the source you read (Lee), and not the original source, as a Works Cited entry.

How to cite a source within a source in Chicago

Chicago style also advises that the practice of citing a source via another source “is generally to be discouraged, since authors are expected to have examined the works they cite.” In the case that the original source is unavailable, Chicago’s Notes/Bibliography format contrasts with MLA and APA, as both sources must be included in the notes, as well as in the bibliography if one is required:

Considering the emergency signalled by climate change out of control, one might argue, “We need a Marshall Plan for the Earth.”1


  1. Angélica Navarro Llanos, “Climate Debt: The Basis of a Fair and Effective Solution to Climate Change” (presentation, Technical Briefing on Historical Responsibility, Ad Hoc Working Group on Long-Term Cooperative Action, United Nations Framework Convention on Climate Change, Bonn, Germany, June 4, 2009), quoted in Naomi Klein, This Changes Everything: Capitalism vs. The Climate (Toronto, ON: Simon & Schuster, 2014), 5.

It might almost feel like as much work to cite this way as it usually would be to track down the original! In this case, however, the original source was one that was difficult to find, being from a presentation at a convention from several years ago.

Fortunately, Chicago Notes/Bibliography style allows a shortened form of the note to be used after you cite the complete information the first time:

To give more detail, “This plan must mobilize financing and technology transfer on scales never seen before.”2

Shortened footnote:

  1. Llanos, “Climate Debt,” quoted in Klein, This Changes Everything, 5.

It’s a little more manageable in Chicago’s Author/Date format. The author and date of both sources should be mentioned in text, while the original source should be excluded as a reference entry:

Considering the emergency signaled by climate change out of control, Angélica Navarro Llanos declared in 2009, “We need a Marshall Plan for the Earth” (quoted in Klein 2014, 5).

Final thoughts

Every assignment and discipline has unique requirements for both writing and citing. However, now that you know how to cite one source’s information from another, be sure to use this method wisely, and seek out the original source when possible. You’re sure to be rewarded for your efforts!


Sarah-Jean Watt, Write Site coordinator

For more questions about citing via secondary sources, contact

The Write Site offers services that support AU students with academic writing. With support from the Write Site’s writing coaches, learners can discuss writing questions and receive feedback about the writing aspects of assignments. Writing coaching is usually most helpful when a learner’s goal is to develop writing skills within the context of course work over time.

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  • March 24, 2022
Guest Blog from:
Sarah-Jean Watt, Write Site coordinator