When writing a paper or article where you’ve used a PDF file as a source, you might be unsure of exactly how to cite it. While it can seem a bit confusing at first, when you look at it as citing what is contained in the PDF file rather than the file itself, it actually becomes a pretty straightforward process.
A PDF file is just a container, after all; a way to display the source. The actual source can be a wide variety of things, such as a book, a magazine or a newspaper. So for the most part you will cite the PDF the same way you would that source in print.
Citing a PDF in MLA style
Say the source PDF is a magazine, you cite it as you would any other magazine article. The main difference, when citing in MLA format, is adding a note to the end that specifies the source is a PDF file rather than print. Here is how you do so:
Author(s). “Article Title.” Magazine Title Date Month Year Published: Page(s). PDF file.
As you can see, you cite in the order of author name, article title, magazine title, date published, page numbers, and finally the medium. And specifying that the medium is a PDF file is actually optional in MLA 8.
If you are accessing the PDF from a website, you will also need to specify the website from which you accessed the file and the date you did so. Here is an example of what that would look like using The New York Times International Edition:
Bradley, Kimberly. “Berlin’s art scene goes on, but with less hype.” vk.com, New York Times International Edition, 19 August 2020, https://vk.com/doc479697494_565494315?hash=cefb3d42c5b51b31f2. Accessed 19 August 2020. PDF file.
So the formatting goes: Author’s Last Name, First Name. “Title of Article: Subtitle if Any.” Title of website, Name of Newspaper, Date of Publication, URL. Accessed access date. And then optionally the medium.
The exact formatting will vary slightly depending on the source and what version of MLA you are using, but this guide should help you properly cite pretty much any PDF in MLA. For further details you can consult resources on MLA formatting like Purdue University’s website.
Citing a PDF in APA style
The process of citing a PDF in APA is much the same, just with the different formatting of APA. If the PDF is a magazine or other online periodical, for example, you would cite it as you would any other periodical. With APA 6 the main differences are that you specify it’s a PDF by putting “PDF File” in square brackets and include the URL from which you accessed it. Here’s how the formatting looks:
Author(s). (Date). Title of article [PDF file]. Title of Online Periodical, Volume number (issue number if available), pages. Retrieved from http://www.example.com/
As you can see, the order is author, date, article title, PDF file in brackets, title of the periodical, volume number, issue number, pages and then finally “Retrieved from” with the full URL of where you accessed the PDF file, usually ending in “.pdf”. You can also use the DOI (Digital Object Identifier) of the PDF instead of the URL.
A DOI is a unique string of alphanumeric characters that persistently identifies many kinds of digital objects, usually things like journal articles and research reports. They are most often used by scholarly publishers. Below is an example of what a citation using a DOI looks like using the journal Nature:
Viswanathan, T., Arya, S., Chan, S., Qi, S., Dai, N., Misra, A., . . . Gupta, Y. K. (2020). Structural basis of RNA cap modification by SARS-CoV-2 [PDF file]. Nature Communications, 11(1), 3-4. doi:10.1038/s41467-020-17496-8
By using this DOI, no matter where you accessed the article or in what form, anyone will be able to find it by searching that string of characters. And other than the inclusion of “PDF file” in brackets, this citation is actually identical to how the article would be cited in print.
Knowing this and following the formatting examples should make it easy to cite all of your PDF sources in APA style. As with MLA, you can consult resources like Purdue University’s website for more details on APA citation formatting.
Citing a PDF in Chicago style
As with MLA and APA, citing a PDF in Chicago style is very similar to how a source in print is cited. The main differences are to list the URL from which the file was accessed, and optionally, to identify that the source is a PDF file. Here’s how that looks:
Author(s). “Title of article.” PDF file. Title of Online Journal Volume number, Issue number
(Year published): page(s). http://example.com
Instead of the URL you can also use the DOI (Digital Object Identifier) of that article; in fact it may be preferred to do so. As explained before, a DOI is a unique identifier that makes it easy to find the article no matter when or where it was accessed.
Here’s what a Chicago style citation with a DOI looks like using an article from the journal Nature as an example:
Viswanathan, Thiruselvam, Shailee Arya, Siu-Hong Chan, Shan Qi, Nan Dai, Anurag Misra, Jun-Gyu Park, et al. “Structural Basis of RNA Cap Modification by SARS-CoV-2.” Nature Communications 11, no. 1 (2020): 3–4. https://doi.org/10.1038/s41467-020-17496-8.
In this example the DOI is cited with a link to the DOI System website, but it can also be cited like by having “doi:” followed by the string of characters.
In some cases you may also need to cite the date that you accessed the source depending on what it is. As before, for more information on how to cite different web sources, you can consult Purdue University’s website on Chicago style formatting.