Answered By: Jennifer Harris
Last Updated: Dec 17, 2018     Views: 28055

A secondary source is a source cited within another source. Sometimes, this is called an indirect source. It is always recommended to locate and cite the original source whenever possible, but there are times when the original source is unavailable (e.g. it’s out of print, in a language other than English, or difficult to obtain through usual sources, etc.). If that’s the case, you may find that you need to cite the secondary source instead.

Generally speaking, to cite a secondary source, you would cite the original source in the text of your paper, but you would provide a reference to the secondary source in the reference list.

Here are examples of how it works in the three major citation styles:

APA Style

Per the APA Manual (6th edition), p. 178 you only want to use secondary sources very rarely (try your best to find the original source and cite it).  The APA Manual indicates that you want to include the secondary source in your reference list. The in-text citation will indicate the original work. 

For example:

In-text citation:

The study by Chueh et al (as cited in Kumar, Sarkar, Saha, and Equebal, 2017)...

Corresponding Reference entry:

Kumar, R., Sarkar, B., Saha, S., & Equebal, A. (2017). Efficacy of myofascial release technique in chronic plantar fasciitis: A randomized controlled trial. Indian Journal Of Physiotherapy & Occupational Therapy, 11(1), 118-123. doi:10.5958/0973-5674.2017.00023.5

For additional examples of citing secondary sources in APA Style, check out the APA Style Blog’s post on Secondary Sources.

MLA Style

The MLA Handbook (8th edition), p. 124 states that you should use the original source if you can find it.  However, if you need to cite an indirect source, as the manual refers to secondary sources, if what you quote or paraphrase is itself a quotation, put the abbreviation qtd. in (“quoted in”) before the indirect source you cite in your parenthetical reference. (You may wish to clarify the relation between the original and secondhand sources in a note.)


George Washington described his meeting with French officers, then a twenty-one year old, in his diaries and explained that the wine the officers drank “banished their restraint” (qtd in Berine 450).

Works Cited:

Beirne, Logan. Blood of Tyrants : George Washington & the Forging of the Presidency. Encounter Books, 2013. EBSCOhost,

For an additional example of citing indirect sources in MLA Style, check out the Purdue OWL.

Chicago Style

Per the Chicago Manual of Style (17th edition) you want to try your best to find the original source and cite that.  However, if that isn't possible, the general formats are described below.

Notes and Bibliography Method

Both the original and the secondary sources must be listed in the note; however, only the secondary source appears in the reference list (see Section 14.260: Citations taken from secondary sources):

General Format:

1. AuthorFirstName AuthorLastName, Title of Book (Place, Publisher, Year), page number(s), quoted in AuthorFirstName AuthorLastName, Title of Book (Place, Publisher, Year), page number(s).

2. AuthorFirstName AuthorLastName, "Title of Article," Title of Journal vol#, no.(issue#) (Date): page number(s), quoted in AuthorFirstName AuthorLastName, Title of Book (Place, Publisher, Year), page number(s).

Note Example:

2. Louis Zukofsky, “Sincerity and Objectification,” Poetry 37 (February 1931): 269, quoted in Bonnie Costello, Marianne Moore: Imaginary Possessions (Cambridge, MA: Harvard University Press, 1981), 78.

Bibliography Example:

Costello, Bonnie. Marianne Moore: Imaginary Possessions. Cambridge, MA: Harvard University Press.

Author-Date References

If an original source is unavailable, and “quoted in” must be resorted to, mention the original author and date in the text, and cite the secondary source in the reference list entry. The in-text citation would include the words “quoted in” (see Section15.56“Quoted in” in author-date references):

In-text Example:

In Louis Zukofsky’s “Sincerity and Objectification,” from the February 1931 issue of Poetry magazine (quoted in Costello 1981) . . .

Reference List Example: 

Costello, Bonnie. 1981. Marianne Moore: Imaginary Possessions. Cambridge, MA: Harvard University Press.

For an additional example of citing secondary sources in Chicago Style, check out the Purdue OWL.

More information:

For further help please contact the Wolak Learning Center at 603.645.9606 (UC./On-Campus Students) and Online Writing Center at 866.721.1662 (Online/COCE Students) for assistance with citations.

This information is intended to be a guideline, not expert advice. Please be sure to speak to your professor about the appropriate way to cite a secondary source in your class assignments and projects.


American Psychological Association. (2010). Publication manual of the American Psychological Association. Washington, D.C.: American Psychological Association.

McAdoo, T. Secondary sources (aka how to cite a source you found in another source) [Blog post]. Retrieved from

The Modern Language Association of America. (2016). MLA Handbook. New York: Modern Language Association of America.

University of Chicago. (2017). The Chicago Manual of Style. Chicago: University of Chicago Press.

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