A secondary source is a work you haven't read directly but encountered through another source's discussion of it. In Harvard referencing, you signal this with the phrase "cited in" — identifying the original author and the source you actually consulted. Only the source you read appears in the reference list; the original work does not, because you cannot verify its content first-hand.
What Is a Secondary Source?
Imagine you're reading a textbook by Okafor (2022). In Chapter 3, Okafor discusses a study by Harris (2005). You want to mention Harris's finding in your essay — but you haven't read Harris's original paper. You only know about it from Okafor's textbook.
In this situation:
- Harris (2005) is the original (primary) source — the work that contains the finding
- Okafor (2022) is the secondary source — the work you actually read
You must tell your reader that you accessed Harris's work indirectly, through Okafor. This is what "cited in" does.
When Is Secondary Citing Acceptable?
Secondary citing is a compromise — it's better than not citing at all, but it's never the preferred approach. Use it only when:
- The original source is out of print or unavailable through your library
- The original is in a language you cannot read
- The original is an unpublished work (e.g., a personal communication mentioned in a textbook)
- You're under time pressure and cannot obtain the original before your deadline (acknowledge this limitation)
In all other cases, track down the original source. Your university library's interlibrary loan service, Google Scholar, and open-access repositories make most published work accessible.
Why it matters:When you cite secondary sources, you're trusting the secondary author's interpretation. They may have paraphrased inaccurately, taken the finding out of context, or cited a superseded edition. Reading the original lets you form your own judgement.
In-Text Citation Format
The in-text citation names the original author first, then the source you read:
Parenthetical:
(Harris, 2005, cited in Okafor, 2022, p. 41)
Narrative:
Harris (2005, cited in Okafor, 2022, p. 41) found that bilingual children outperformed monolingual peers on attentional control tasks.
Or, if you lead with the secondary source:
Okafor (2022, p. 41) discusses Harris's (2005) finding that bilingual children outperformed monolingual peers on attentional control tasks.
Key Formatting Details
| Element | Rule |
|---|---|
| Original author | Comes first — give credit to the person whose work you're referencing |
| Secondary author | Follows "cited in" |
| Page number | Include the page from the secondary source where the discussion appears |
| Year for original | If the secondary source gives the year, include it. If not, omit it |
Variation: "As Cited In"
Some Harvard guides use "as cited in" instead of "cited in":
(Harris, 2005, as cited in Okafor, 2022, p. 41)
Both forms are widely accepted. Check your institution's preferred wording and use it consistently.
What Goes in the Reference List
Only the source you actually read appears in the reference list. The original source does not get its own entry.
Reference list (include):
Okafor, D. (2022) Language and cognition: a developmental perspective. 3rd edn. London: Routledge.
Reference list (do NOT include):
Harris, P. (2005) 'Attentional control in bilingual children', Journal of Child Psychology, 46(3), pp. 215–230.
This rule exists because you haven't verified Harris's original work — you only know what Okafor reported about it. Including Harris in the reference list would imply you read the paper, which would be misleading.
Examples
Textbook Citing an Original Study
A psychology textbook by Fernandez (2023) references a classic experiment by Milgram (1963):
In-text:
Milgram's (1963, cited in Fernandez, 2023, p. 112) obedience experiments demonstrated that ordinary people would administer what they believed were dangerous electric shocks when instructed by an authority figure.
Reference list:
Fernandez, R. (2023) Social psychology: key concepts and applications. 2nd edn. Cambridge: Cambridge University Press.
Review Article Citing Data From Another Paper
A review by Torres and Kim (2024) mentions survey data originally collected by Patel (2019):
In-text:
Patel (2019, cited in Torres and Kim, 2024, p. 305) reported that 67% of UK undergraduates experienced citation anxiety at least once during their degree.
Reference list:
Torres, M. and Kim, J. (2024) 'Citation practices in higher education: a systematic review', Studies in Higher Education, 49(2), pp. 298–315. doi:10.1234/she.2024.0049.
Lecture Slides Citing a Published Source
Your lecturer, Dr Ahmed, includes a chart from a World Bank (2020) report in a slide deck. You haven't accessed the World Bank report directly:
In-text:
The World Bank (2020, cited in Ahmed, 2024) estimated that global poverty rates fell by 1.2 percentage points between 2015 and 2019.
Reference list:
Ahmed, S. (2024) 'Week 5: Global inequality' [Lecture slides]. EC2010: Development Economics. University of Leeds. 18 February.
How to Find and Access the Original Source
Before defaulting to "cited in," try these steps to locate the original work:
- Check the reference list of the secondary source. It should contain a full citation for the original. Copy the title or DOI.
- Search your library catalogue or database using the title, author, or DOI.
- Use Google Scholar. Paste the title in quotation marks to find the original paper.
- Try open-access repositories — many authors deposit preprints or accepted manuscripts in repositories like PubMed Central, SSRN, or their institutional repository.
- Request an interlibrary loan. If your library doesn't hold the source, they can usually obtain it from another institution within a few working days.
If you find the original source, read it and cite it directly — you no longer need "cited in."
Common Mistakes With Secondary Sources
| Mistake | Why It's Wrong | Correct Approach |
|---|---|---|
| Including the original source in the reference list | You haven't read it — listing it implies you have | Only list the source you actually read |
| Omitting "cited in" | Without it, you imply you read the original | Always use "cited in" (or "as cited in") |
| Putting the secondary author first | The original author's idea should be credited first | Name the original author first, then "cited in" + secondary author |
| Using secondary sources excessively | It signals shallow engagement with the literature | Track down originals wherever possible |
| Forgetting the page number for the secondary source | The reader needs to locate the passage | Include the page number from the source you read |
| Citing a secondary source of a secondary source | Creates a chain of unverified references | Go back to the earliest accessible source and cite that |
What's Next?
Now that you know how to handle secondary sources, explore these related guides:
- Harvard In-Text Citations — the complete guide to all in-text citation formats
- Harvard Reference List — alphabetical ordering, formatting rules, and examples for every source type
- How to Paraphrase in Harvard Referencing — rules for paraphrasing sources in your own words
