How to cite a source you found inside another source

A secondary citation is what you write when you use an idea or a quotation from a work you have not read yourself, and you found it inside a work you did read. The work you read is the secondary source. The work it mentions is the original, or primary, source. Teachers also call this an indirect citation or secondary referencing.

Every major style handles it the same way at heart. You name the original in your text, you show that you met it through the second work, and you list only the second work at the end of the paper. The wording and the punctuation differ by style. This post gives the exact form for APA 7, MLA 9, Chicago 18 and Harvard (Cite Them Right), with invented authors in every example.

The general post on how to cite sources in your paper shows the short version in APA and MLA. This one goes further.

Try to find the original first

All four styles discourage secondary citations when the original can be found.

• APA says to cite secondary sources sparingly, for example when the original is out of print, cannot be obtained, or is in a language you cannot read. As a matter of good practice, it says to find the original, read it and cite it.
• MLA says you are not required to check a quotation you take from another source, but that it is always best to consult the original and quote from it directly when you can.
• Chicago says citing a source “quoted in” another work is generally discouraged, because authors are expected to have examined the works they cite.
• Harvard guides based on Cite Them Right give the same advice. Newcastle University’s style sheet says to try to find and read the original first, so you do not take the material out of context. UWE Bristol warns that the author you read may have used the original for a different purpose than yours.

There is a practical reason too. Each time a quotation is copied, it can change. A word drops out, a page number shifts, or a summary bends the original claim. If you cite the original after reading it, those errors are not yours.

The example used below

Say you are reading a book by Karin Brandt and Mei Liu, Reading Habits in Rural Schools, published in 2021 by Halden Press. On page 44 they quote a 2009 book by Teresa Okafor. You cannot get Okafor’s study. Brandt and Liu is the work you read, so it is the secondary source. Okafor is the original.

APA 7

In the text

Name the original, write “as cited in”, then name the source you read.

• Parenthetical: (Okafor, 2009, as cited in Brandt & Liu, 2021)
• Narrative: Okafor (2009, as cited in Brandt & Liu, 2021) found that…

APA says to include the original’s year when you know it, which gives two years in one citation. If the original’s year is not known, leave it out: (Okafor, as cited in Brandt & Liu, 2021).

For a direct quotation, APA requires a page number. Give the page of the source you read, where your reader will find the words: (Okafor, 2009, as cited in Brandt & Liu, 2021, p. 44).

In the reference list

Only the source you read gets an entry. APA states this directly. Okafor does not appear.

Brandt, K., & Liu, M. (2021). Reading habits in rural schools. Halden Press.

MLA 9

In the text

MLA uses “qtd. in”, short for “quoted in.” The MLA Style Center shows three places the original author’s name can go:

• In your sentence: According to Teresa Okafor, rural pupils “read most when the books come to them” (qtd. in Brandt and Liu 44).
• In the parentheses: (Teresa Okafor qtd. in Brandt and Liu 44)
• In an endnote, with a superscript number after the quotation.

The page number is the page of the book you read. MLA does not use a year in the in-text citation, so the question of two years does not come up.

In the Works Cited list

List only the work you consulted. In the MLA Style Center’s example, a quotation of Alexander Pope found in a book by Leopold Damrosch has a Works Cited entry for Damrosch only.

Brandt, Karin, and Mei Liu. Reading Habits in Rural Schools. Halden Press, 2021.

Paraphrasing in MLA

“Qtd. in” is for quotations. When you paraphrase material that the work you read took from somewhere else, MLA says to cite the work you read and to make clear to your reader that you did not consult the original. You can do this in your sentence: Brandt and Liu report that Okafor’s survey found rural pupils read more when books were brought to their classrooms (44). That MLA Style Center page was written for the eighth edition, so check the ninth edition Handbook if your instructor is strict about it.

Chicago 18

Notes and bibliography

Chicago’s own Q&A says that if the original is unavailable, both the original and the secondary source must be listed. In a note, you give the original first, then “quoted in”, then the source you read, ending with its page number. The Q&A’s example cites an article from 1931 as quoted in a book from 1981.

1. Teresa Okafor, Small Libraries, Large Readers (Northgate Press, 2009), 12, quoted in Karin Brandt and Mei Liu, Reading Habits in Rural Schools (Halden Press, 2021), 44.

Take the details of the original from the source you read. If Brandt and Liu give Okafor’s page number in their own notes, use it. If they do not, leave it out.

The bibliography is where guides disagree. McGill University Library’s Chicago 18 guide says to include both the original and the secondary source. Other university guides list only the work you read. Chicago’s online Q&A does not show a bibliography entry. Ask your instructor, and if there is no answer, list both, which is the safer reading of Chicago’s guidance.

Author-date

In Chicago’s author-date system, Sacramento State’s library guide shows the original author named in the text and “quoted in” with the secondary source in the parentheses. The reference list has the secondary source. McGill’s guide lists both the original and the secondary source in author-date too, so the same advice applies: ask, and if in doubt list both.

Okafor found that rural pupils “read most when the books come to them” (quoted in Brandt and Liu 2021, 44).

Harvard (Cite Them Right)

Harvard has no single official manual. Most UK universities follow Cite Them Right. Newcastle University’s 2025 style sheet for it gives two phrases: “quoted in” for a quotation and “cited in” for an idea. Both include the page of the source you read.

• Quotation: Okafor (2009, quoted in Brandt and Liu, 2021, p. 44) states that rural pupils “read most when the books come to them”.
• Idea: Okafor’s survey of rural pupils (2009, cited in Brandt and Liu, 2021, p. 44) suggests that…

Cite Them Right joins two author names with “and”, not an ampersand. Some universities use “cited by” or “citing” instead. UWE Bristol’s examples use that wording. Follow the version your university publishes.

The reference list has the source you read and nothing else. Newcastle’s sheet says to cite only the source you read in your reference list.

Brandt, K. and Liu, M. (2021) Reading habits in rural schools. Halden Press.

Quick reference

In every style, the page number belongs to the source you read.

Common mistakes

• Listing the original as if you read it. In APA, MLA and Harvard, the original does not go in the list at the end. Listing it claims you read it.
• Leaving out the original. Citing only Brandt and Liu for Okafor’s words credits the wrong author.
• Giving the original’s page number in APA, MLA or Harvard. The page in the citation is where your reader finds the words, which is in the source you read.
• Dropping the original’s year in APA when you know it. APA wants both years.
• Mixing the phrases. “As cited in” is APA. “Qtd. in” is MLA. “Quoted in” or “cited in” is Chicago and Harvard. Each one in the wrong style looks like a slip.
• Using a secondary citation for a source you could find. Many originals are one search away, and the steps below take a few minutes.

One thing you may leave out: MLA says you can drop the notes and parenthetical citations that appear inside a passage you quote.

How to find the original

Start with the work you read. A cited quotation will have a citation of its own, and its reference list or notes will give the original’s author, year and title. MLA makes this point when it says readers can find the original in the secondary work’s citations.

With those details:

1. Search the exact title in quotation marks on Google Scholar. The “All versions” link under a result often leads to a free copy from the author or a university repository.
2. Look for a DOI. A journal article usually has one, and a DOI link opens the publisher’s page. The post on how to find a DOI shows where to look.
3. Search your library catalogue for books and older articles. If your library does not hold it, ask about interlibrary loan.
4. Check that the original says what the second work claims. Read the page around the quotation. If the wording differs, quote the original.

Once you have the original, cite it as a normal source and drop the secondary form. If you also used the second work for its own ideas, cite it separately.

Checking the result

A reference list built from secondary sources is a common place for errors to collect, because details are copied from someone else’s list. The reference checker looks up each entry against the published record and flags one whose authors, year or title do not match. It will also tell you when an original you tracked down has been retracted.