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Data Correlation: Citations

Resources for the Math IA

MLA Reference and In-text Citation

From OWL at Purdue

Citing indirect sources

Sometimes you may have to use an indirect source. An indirect source is a source cited in another source. For such indirect quotations, use "qtd. in" to indicate the source you actually consulted. For example:

Ravitch argues that high schools are pressured to act as "social service centers, and they don't do that well" (qtd. in Weisman 259).

Note that, in most cases, a responsible researcher will attempt to find the original source, rather than citing an indirect source.

Paraphrased in Your Prose

While the green light in The Great Gatsby might be said to chiefly symbolize four main things: optimism, the unattainability of the American dream, greed, and covetousness (“Describe the symbolism”), arguably the most important—the one that ties all four themes together—is greed.

Works-Cited-List Entry

“Describe the symbolism of the green light in the book The Great Gatsby by F. Scott Fitzgerald” prompt. ChatGPT, 13 Feb. version, OpenAI, 8 Mar. 2023,


Quoted in Your Prose

When asked to describe the symbolism of the green light in The Great Gatsby, ChatGPT provided a summary about optimism, the unattainability of the American dream, greed, and covetousness. However, when further prompted to cite the source on which that summary was based, it noted that it lacked “the ability to conduct research or cite sources independently” but that it could “provide a list of scholarly sources related to the symbolism of the green light in The Great Gatsby” (“In 200 words”).

Works-Cited-List Entry

“In 200 words, describe the symbolism of the green light in The Great Gatsby” follow-up prompt to list sources. ChatGPT, 13 Feb. version, OpenAI, 9 Mar. 2023,

From OWL at Purdue

Citing authors with same last names

Sometimes more information is necessary to identify the source from which a quotation is taken. For instance, if two or more authors have the same last name, provide both authors' first initials (or even the authors' full name if different authors share initials) in your citation. For example:

Although some medical ethicists claim that cloning will lead to designer children (R. Miller 12), others note that the advantages for medical research outweigh this consideration (A. Miller 46).

Citing a work by multiple authors

For a source with two authors, list the authors’ last names in the text or in the parenthetical citation:

Best and Marcus argue that one should read a text for what it says on its surface, rather than looking for some hidden meaning (9).

The authors claim that surface reading looks at what is “evident, perceptible, apprehensible in texts” (Best and Marcus 9).

Corresponding works cited entry:

Best, David, and Sharon Marcus. “Surface Reading: An Introduction.” Representations, vol. 108, no. 1, Fall 2009, pp. 1-21. JSTOR, doi:10.1525/rep.2009.108.1.1

For a source with three or more authors, list only the first author’s last name, and replace the additional names with et al.

According to Franck et al., “Current agricultural policies in the U.S. are contributing to the poor health of Americans” (327).

The authors claim that one cause of obesity in the United States is government-funded farm subsidies (Franck et al. 327).

Corresponding works cited entry:

Franck, Caroline, et al. “Agricultural Subsidies and the American Obesity Epidemic.” American Journal of Preventative Medicine, vol. 45, no. 3, Sept. 2013, pp. 327-333.

Citing multiple works by the same author

If you cite more than one work by a particular author, include a shortened title for the particular work from which you are quoting to distinguish it from the others. Put short titles of books in italics and short titles of articles in quotation marks.

Citing two articles by the same author:

Lightenor has argued that computers are not useful tools for small children ("Too Soon" 38), though he has acknowledged elsewhere that early exposure to computer games does lead to better small motor skill development in a child's second and third year ("Hand-Eye Development" 17).

Citing two books by the same author:

Murray states that writing is "a process" that "varies with our thinking style" (Write to Learn 6). Additionally, Murray argues that the purpose of writing is to "carry ideas and information from the mind of one person into the mind of another" (A Writer Teaches Writing 3).

Additionally, if the author's name is not mentioned in the sentence, format your citation with the author's name followed by a comma, followed by a shortened title of the work, followed, when appropriate, by page numbers:

Visual studies, because it is such a new discipline, may be "too easy" (Elkins, "Visual Studies" 63).

MLA Citations

Book with one author

Last name, First name. Title of source. Publisher, date of publication.

EX: Fleming, Thomas. Liberty! The American Revolution. Viking. 1997

Parenthetical (Fleming 38)

Book by multiple authors

Last name, First, and First name, Last. Title of Source. Publisher, date of publication

EX: Thorn, Roger and June Cartwright. The Hummingbird House. Macmurray, 1999.

Parenthetical (Thorn and Cartwright 123)


List the works alphabetically, by title (ignore words like "the" and "an.") Provide author's name for first title only

EX:  Hartford, William J. Austen and New Historicism. St. Martin's, 1987.

            -----                     Movies of the Sixties: A Social History. Southern Illinois UP, 1993.  


 Label images / charts / maps:   Fig 1, Fig 2, etc

CITATION: Artist. Title (or description) of Source. Name of container, publisher, publication date. URL

EX1 (painting): Goya, Francisco. "The Family of Charles IV."  Museo Nacional del Prado, May 22.

EX2 (photo)   Applewhite, Scott.  "U.S. President Trump giving speech." The Guardian, Guardian News and Media, Mar 3,     2018.                   

Parenthetical: (see Fig. 1)

TABLES:  Do the same, but call them Table 1, Table 2  etc.


Article from an online database:  You may have ONE or TWO containers to document here, depending on whether the source article comes from a journal, or was written by the database company.

Last name, First. Title of Source. Title of Container 1 (e.g. name of journal). Volume, number, date of publication, location (pg #s). Title of Container 2 (database). URL

EX: Langhamer, Clare. "Love and Courtship in Victorian England." Historical Journal. Vol 5o. No 1. pp. 173-86. ProQuest

Name of subject. Personal Interview. Date

EX: Whitehurst, Daniel.  Personal Interview. 5 Mar 2003.

Email interview

Author. "Subject Line." Message to your name. Date.

EX:  Depp, Johnny.  "RE: Your Artistic Vision." Message to Erica Jonsdottr. 1 Dec 2003.



Last Name, First (of the uploader). "Video Title." Title of Container. Role of relevant contributors, first and last names. Publisher, publication date, Location.

EX:  Run4u. "See Spot Run." YouTube. 1 Feb 2005.

EX: "Gene Map of Brain Offers Hope." The News Hour with Jim Lehrer. Producer, Muhammad Ahmed. PBS. 2 Feb 2010.


For Films, documentaries, etc. The names you include depend on your focus: Director if you're discussing the film in general, actors if you're looking at performance, Screenwriter if you're looking at dialogue, etc.

Last Name, First (role). Title of Film.  Studio/Distributor. Year published.

EX:  Scorsese, Martin (director).  Shutter Island. Paramount, 2010.

Let's say you're reading  your Econ textbook, and they quote Paul Krugman saying something brilliant about economic theory.  You want to use that quotation in your essay.  Here's how you do it:

1) Cite your Econ textbook in the Works Cited list.

            Ziogas, Constantine. Economics for the IB Diploma. Oxford University Press, 2014.

2)  In your essay, use the quotation. Your parenthetical mentions the author you're quoting, and where the quote came from.

                   Krugman argues that Keynesian "trickle down" theory left the country in economic tatters (Krugman, qtd in Ziogas  38).

Author of quoted source. "Title of article or speech." Title of publication (if available). "Title of Handout." Handout. Name of course. (Name of teacher). Name of school. Date of handout.

EX:  King, Martin Luther Jr. . "I Have a Dream."  Famous Speeches for Analysis. Handout. Language and Literature, (Darren Rix). WAB, Mar 2013.

If the author is named, include it. Otherwise, just use the title of the page.  Also be careful:  there are different types of websites: Online newspapers/magazines, blogs, etc. 

Author. "Title of Source." Title of Website.  Publisher, date published. URL

EX:  Clapton, Jennifer. "Exercise Yourself to Death?" WebMD. 22 Feb 2018.

EX:  Krugman, Paul. "A Ranting Old Guy with Nukes." New York Times. New York Times Company. 03 March 2018.

When using sources in another language , you must translate names and titles into their English versions.  Put the translation in parenthesis behind the original.  See below for examples.


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