You’re reading a source for your paper, and inside it, the author quotes a completely different study, one that’s out of print, locked behind a paywall you can’t get past, or written in a language you don’t read. You need to reference that original idea, but you never actually read the original yourself. Here’s the exact format for both styles, so you can cite it correctly without pretending you read something you didn’t.
| APA in-text citation (Original Author, Year, as cited in Source You Read, Year) Example: (Rabbitt, 1982, as cited in Lyon et al., 2014) Narrative version: Rabbitt (1982, as cited in Lyon et al., 2014) found that… MLA in-text citation (qtd. in Source You Read, Page) Example: (qtd. in Mann 835) The rule that trips people up most: in both styles, only the source you actually read goes in your reference list or works cited page. The original source you never touched does not get its own entry. |
What Actually Counts as a Secondary Source
A secondary source, in this context, isn’t just any source that isn’t a primary document. It specifically means a source you’re citing indirectly, where you learned about an idea or a quote only because another author mentioned it, not because you read the original work yourself.
This comes up more than students expect. A textbook might summarize a classic study from decades ago. A journal article you found through your library database might quote an older paper that was never digitized. A source might simply be written in a language you can’t read, so you’re relying entirely on someone else’s translation and summary of it.
In all of these cases, the fix is the same: you cite the original author by name in your sentence, then credit the source you actually read for leading you to that information.
Should You Even Use a Secondary Citation, or Go Find the Original?
Both APA and MLA are direct about this: secondary citations are a fallback, not a shortcut. Both style guides expect you to track down and read the original source whenever it’s realistically possible, and to only fall back on a secondary citation when the original genuinely isn’t available to you.
There’s a real academic reason behind this, not just a formatting rule. A secondhand summary can distort or oversimplify what the original source actually argued, sometimes without the second author even meaning to. If that original idea matters enough to your argument to cite, it’s worth the extra ten minutes to check whether your library or a database actually has access to it before you default to citing it secondhand. You can also use Skyline’s plagiarism checker to review your work before submission and identify potential text overlap that may need proper citation.
This is also where citation shortcuts start blurring into bigger issues. Leaning on secondary citations too often, instead of engaging with the sources yourself, can start to look like you haven’t actually done the reading your paper claims to be based on. If you’re unsure where that line sits, different types of plagiarism is worth a read alongside this guide, since sourcing shortcuts and plagiarism concerns overlap more than most students realize.
How to Cite a Secondary Source in APA Format
APA’s official guidance on this is built around one phrase: “as cited in.” You name the original author first, since they’re the one whose idea or words you’re actually referencing, then credit the source where you actually found it.
The parenthetical version places both names and years together at the end of the sentence: (Rabbitt, 1982, as cited in Lyon et al., 2014). The narrative version works the original author’s name into your own sentence directly, then tucks the “as cited in” reference into parentheses right after: Rabbitt (1982, as cited in Lyon et al., 2014) found that early reading difficulties were linked to specific processing delays.
Either way, your reference list entry only includes Lyon et al., the source you actually read. Rabbitt’s original 1982 work does not get its own reference list entry, since you never read it directly. This exact rule comes straight from the official APA Style guidance on citing secondary sources, which also notes that secondary citations should be used sparingly, specifically when the original text truly isn’t accessible.
How to Cite a Secondary Source in MLA Format
MLA uses a different phrase for the same situation: “qtd. in,” short for “quoted in.” There’s an important detail here that APA doesn’t have: MLA’s “qtd. in” format is specifically meant for direct quotes you’re borrowing through a secondary source, not just any paraphrased idea.
In practice, you name the original author in your sentence, then place “qtd. in,” followed by the secondary source’s author and a page number, in parentheses right after the quote. A full example: According to Rushdie, myths are “the waking dreams our societies permit” (qtd. in Mann 835).
Just like APA, only the source you actually read goes on your works cited page. Mann’s article would get a full entry; Rushdie’s original comment would not. This mirrors the MLA Handbook’s own guidance on indirect sources, which is consistently reflected across university MLA style guides even though MLA’s public style center doesn’t have a single dedicated blog post on the topic the way APA does.
APA vs MLA at a Glance
If you just need the two side by side to double check you’re using the right phrase, here’s the quick comparison.
| APA | MLA | |
| Key phrase | as cited in | qtd. in |
| Works for | Paraphrased ideas and direct quotes | Direct quotes specifically |
| In-text example | (Rabbitt, 1982, as cited in Lyon et al., 2014) | (qtd. in Mann 835) |
| Reference list or works cited | Only the source you read | Only the source you read |
Common Mistakes Students Make With Secondary Sources
Most secondary source mistakes come down to a handful of repeat offenders, and they’re easy to catch once you know what to look for.
| Mistake | The fix |
| Citing the original author’s work in your reference list even though you never read it | Only the secondary source, the one you actually read, gets a reference list or works cited entry |
| Using “qtd. in” for a paraphrase instead of a direct quote in MLA | Reserve “qtd. in” specifically for direct quotations; paraphrased ideas are handled differently |
| Skipping the page number on a direct quote | Always include the page number from the source you actually read, right after the author’s name |
| Defaulting to a secondary citation without checking if the original is available | Search your library database or Google Scholar first, secondary citations should be the fallback, not the first move |
If you want to make sure your citations and sourcing are actually clean before you submit, running your paper through a best plagiarism checker for academics is a quick way to catch anything that slipped through.
What This Has to Do With Citing ChatGPT
This same principle shows up in a newer context too. When ChatGPT or a similar AI tool hands you a source, complete with an author, a title, and a year, that’s functionally the same situation as a secondary source, except it’s riskier, since AI tools sometimes invent sources that don’t exist at all.
Treat anything ChatGPT cites as a lead worth checking, never as something you can cite secondhand straight from the AI’s summary. Find the actual source, confirm it’s real, and read enough of it to cite it properly yourself. If you’re also navigating how to credit ChatGPT directly in your paper, citing a chatgpt in apa and mla covers that exact format side by side.
How Skyline Academic Helps You With Plagiarism
Citation anxiety and plagiarism anxiety usually travel together. Once you’re unsure whether a secondary citation is formatted correctly, it’s easy to start second guessing your entire reference list. Skyline Academic is built to close that gap directly, with free AI detection and plagiarism checking tools that let you verify your sourcing is clean before a professor ever sees it.
Beyond the tools, Skyline offers 1:1 live tutoring support delivered through an interactive LMS dashboard, with structured workshops and bootcamps, a dashboard that tracks your progress across a full semester rather than one assignment at a time, and assignment specific quizzes to check your understanding before submission day. If citation formatting is the part you’re stuck on, a tutor can walk through your actual reference list with you rather than leaving you to guess.
For a broader look at how sourcing mistakes connect to bigger academic integrity concerns, read more insights on plagiarism is worth reading alongside this guide.
Frequently Asked Questions
What is a secondary source citation in APA style?
It’s how you credit an original author whose work you only encountered through another source, using the phrase “as cited in” followed by the source you actually read. Only the source you read goes in your reference list.
How do I cite a quote within a quote in MLA format?
Use “qtd. in” followed by the author and page number of the source you actually read, right after the quoted text. For example: (qtd. in Mann 835).
Do I need to cite the original author if I never read their work?
Yes, name them in your sentence to give credit for the idea, but only the secondary source you actually read gets a full reference list or works cited entry.
Is it okay to use secondary sources in a research paper?
Only sparingly, and mainly when the original source truly isn’t available to you. Both APA and MLA expect you to try to find and read the original whenever it’s realistically possible.
What’s the difference between as cited in and qtd. in?
“As cited in” is APA’s phrase and covers both paraphrased ideas and direct quotes. “Qtd. in” is MLA’s phrase and is meant specifically for direct quotations borrowed through another source.
How do you format an in-text citation for a secondary source in APA?
Name the original author and year, then add “as cited in” followed by the author and year of the source you actually read, all in parentheses. For example: (Rabbitt, 1982, as cited in Lyon et al., 2014).
Does the original source go in my reference list or works cited page?
No, in both APA and MLA, only the secondary source, the one you actually read, gets listed. The original source you never accessed directly is named in your text but not in your reference list.
Can I use qtd. in for a paraphrased idea instead of a direct quote?
Not really, MLA reserves “qtd. in” specifically for direct quotations. A paraphrased idea from a secondary source is still cited, but framed as a paraphrase rather than a quotation.
Why do professors discourage using too many secondary citations?
Secondhand summaries can unintentionally distort what the original source actually said, and relying on them too heavily can suggest you haven’t engaged directly with your sources. Use them as a fallback, not a habit.
What should I do if I can’t find the original source at all?
Check your library database, interlibrary loan, and Google Scholar first. If it’s genuinely unavailable, a secondary citation using “as cited in” or “qtd. in” is the accepted, honest way to reference it.
The Bottom Line
Citing a secondary source isn’t complicated once you remember the core rule: name the original author for credit, cite the source you actually read using “as cited in” or “qtd. in”, and only list the source you read on your reference or works cited page. Try to find the original first when you realistically can, and use the secondary citation as the honest fallback it’s meant to be, not a shortcut.