How to Cite a Research Paper in APA, MLA, Chicago and Harvard

Every citation style asks for the same handful of facts about a journal article and arranges them differently. Once you have the facts, formatting is mechanical. This guide shows the same paper cited four ways.

The details you need

• The authors' names
• The year of publication
• The title of the article
• The name of the journal
• The volume and issue numbers
• The page range, or an article number if the journal does not use pages
• The DOI

All of these appear on the article's page and on the first page of the PDF. If you are unsure what a DOI is, see what a DOI is and where to find it.

The examples below use a well-known paper: "Hallmarks of Cancer: The Next Generation" by Douglas Hanahan and Robert A. Weinberg, published in the journal Cell in 2011, volume 144, issue 5, pages 646 to 674. In every style the journal name is set in italics.

APA (7th edition)

Hanahan, D., & Weinberg, R. A. (2011). Hallmarks of cancer: The next generation. Cell, 144(5), 646–674. https://doi.org/10.1016/j.cell.2011.02.013

APA uses initials for first names, puts the year straight after the authors and writes the article title in sentence case. The volume number is italic along with the journal name. In the text, cite it as (Hanahan & Weinberg, 2011).

MLA (9th edition)

Hanahan, Douglas, and Robert A. Weinberg. "Hallmarks of Cancer: The Next Generation." Cell, vol. 144, no. 5, 2011, pp. 646–74, https://doi.org/10.1016/j.cell.2011.02.013.

MLA gives names in full, puts the article title in quotation marks and labels the volume, issue and pages. In the text, cite the authors and page: (Hanahan and Weinberg 650).

Chicago (notes and bibliography)

Hanahan, Douglas, and Robert A. Weinberg. "Hallmarks of Cancer: The Next Generation." Cell 144, no. 5 (2011): 646–74. https://doi.org/10.1016/j.cell.2011.02.013.

Chicago has two systems. The notes and bibliography system uses footnotes plus a bibliography entry like the one above. The author-date system uses in-text citations such as (Hanahan and Weinberg 2011) and moves the year to follow the authors' names in the reference list.

Harvard

Hanahan, D. and Weinberg, R.A. (2011) 'Hallmarks of cancer: the next generation', Cell, 144(5), pp. 646–674. doi:10.1016/j.cell.2011.02.013.

Harvard is a family of similar styles with no single official version, so details such as punctuation vary between universities. Follow your own institution's guide where it differs from this.

Papers with many authors

Each style shortens long author lists in its own way. In the text, APA and MLA use the first author followed by "et al." for three or more authors, and Chicago does so for four or more. In the reference list the rules differ again, so check your style guide when a paper has more than a few authors.

Which version should you cite?

If you read a free copy of a paper, such as an accepted manuscript from a university repository, cite the published article with its DOI. The content is the same, and the published version is the one your readers can look up. Cite a preprint only when no published version exists, and say that it is a preprint. Our guide to preprints and published papers explains the difference.

A quick way to collect the details

Paste a DOI or title into the finder on our home page. The paper's page shows the authors, journal, year and DOI in one place, alongside any free copy, so you can check your citation against them.