A Guide to Secondary Citations (AMA, APA, Chicago and MLA)

In our Becoming A Proofreader course, we mention that proofreaders should look out for secondary citations when proofreading academic documents. And to help you do this, we’re looking at how some of the major referencing systems approach secondary citations.

What Are Secondary Citations?

In simple terms, a secondary citation is a second-hand citation: i.e., a citation of a citation. Authors use them when they cannot access the original source they want to cite.

Imagine, for instance, you found a quote from an out-of-print book you wanted to use. Because the book is no longer available, it may be very difficult or even impossible to get hold of a copy. But you could still cite the source in which you found the quotation.

To do this, an author should indicate it is a secondary citation via a signal phrase such as “as cited in” or “as quoted in.” But the correct format for this will depend on the referencing system they’re using, and you should look out for errors in this respect while proofreading.

For clarity, we will use the following terminology below:

• Original source = The out-of-print or otherwise unavailable source.
• Secondary source = The source the author has actually read.

Now, let’s look at how secondary citations work in a few major referencing systems.

AMA Referencing

The most recent version of the AMA Manual of Style does not include instructions for secondary citations and quotations, but the previous (10th) edition suggests giving the citation for the original source, followed by “Cited by” or “Quoted by” and the secondary source details:

1. Jones R, Merton B. Inaccessible Sources. Journal of Referencing. 1994;29(1):102-108. Cited by: Smith J. Citing Sources Indirectly. New York, NY: Fictional Publisher; 2001.

In the example above, we give a secondary citation for the Jones and Merton journal article (i.e., the original source that we could not access), which we found cited in a book by Smith. To allow comparison, we will use the same examples for the remaining systems.

APA Referencing

In APA referencing, you signal a secondary citation with the phrase “as cited in.” For example:

According to Jones and Merton’s 1994 study of the scientific papers (as cited in Smith, 2001), most authors struggle to understand secondary citations.

The reference list, meanwhile, should only include the secondary source (not the original source). In this case, then, we would only need to list the Smith source.

Chicago Referencing (Footnotes)

If your client is using Chicago footnote referencing, in the first footnote citation, the author should provide the original source details first, followed by “quoted in,” the secondary source information, and a pinpoint citation for where the original source is cited:

1. Robert Jones and Beryl Merton, “Inaccessible Sources,” Journal of Referencing 29, no. 1 (1994): 102, quoted in Jake Smith, Citing Sources Indirectly (New York, NY: Fictional Publisher, 2001), 45.

Here, for instance, we show that Jones and Merton’s article was cited on page 45 of the Smith book. In the bibliography entry, however, only the secondary source should be listed.

Chicago Referencing (Author–Date)

As with the footnote version of this system, Chicago author–date referencing uses the phrase “quoted in” to signal a secondary citation. For instance:

According to Jones and Merton’s 1994 study of the scientific papers (as quoted in Smith, 2001), most authors struggle to understand secondary citations.

And as above, the author should only include the secondary source in the reference list.

MLA Referencing

MLA referencing uses the abbreviation “qtd. in” to signal a secondary citation:

According to Jones and Merton’s 1994 study of the scientific papers (qtd. in Smith 45), most authors struggle to understand secondary citations.

And as with APA and Chicago, MLA suggests only listing the secondary source in the “Works Cited” list. As such, you should make sure that the original source is not included.

Learn to Proofread Academic Writing

If you would like to learn more about proofreading academic writing and references, or any other aspect of proofreading, check out the courses we have available.