Citing the Literature Correctly Within the Text

Last week we looked at how to describe the literature in the Introduction and Discussion sections of your manuscript. When referring to a published study in the main text of your manuscript, a specific format is required for citing the study. This format is dependent on the number of authors in the study.

Three or More Authors

If citing a study with 3 or more authors, use the last name of the first author, followed by “et al” and then either the citation number from the References list, or the publication year, whichever is the journal’s required format:

A Level II prospective cohort study by Cherney et al² investigated whether …
Hu et al. (2013) evaluated adverse radiological outcomes following …

The “et al” may be written in a normal font or in italics, with or without a period after the “al”. It’s best to check a recent issue of the journal where you plan to submit your paper to see the specific format used by that journal. Most importantly, be consistent with the format throughout your manuscript – either italicize or don’t in every case, and either use a period or don’t in every case.

Alternatively, “et al” can be replaced with “and colleagues”:

A Level II prospective cohort study by Cherney and colleagues² investigated whether …
Hu and colleagues (2013) evaluated adverse radiological outcomes following …

Two Authors

If citing a study with only 2 authors, you must list both author names:

In a Level I study by Hu and Cherney,⁸ …
Kim and Jones (2018) conducted an adequately powered RCT to identify …

A Single Author

If citing a study with only one author, simply list that author’s name:

In a retrospective chart review of … , Wrigley¹¹ determined that …
Hartman (2017) conducted a systemic review of …

Where Does the Citation Number Go?

In the body of the text, the citation number from the Reference list may appear as superscript, or in a full-sized font within either round or square brackets. This number appears directly after “et al” or the last author’s name:

Hu et al.⁵ evaluated adverse radiological outcomes following …
In a Level I study by Hu and Cherney (8), patients …
Kim and Jones [9] conducted an adequately powered RCT to identify …
In a systematic review by Hartman,¹¹ age did not affect …
In a current concepts review by Smith¹⁴, techniques for …

The citation number should appear either before or after any punctuation, depending on the journal’s specific requirements. Again, it’s necessary to check a recent issue of the preferred journal for their required format and follow their format.

When No Authors Are Mentioned

Sometimes one will describe a previous study without mentioning the authors’ names. In this case, the citation number or publication year is placed at the end of the sentence, either before or after the punctuation, depending on the journal’s specific format:

Consideration should be given to …, as is recommended for fragility fractures.¹⁴
At 2 years follow-up, VAS scores improved significantly in 130 patients².
A titanium implant was evaluated prospectively in 38 patients. [12]
Most clinical outcome measures improved significantly at 5 years postoperatively [3].

Remember, the most important formatting rule for citing published studies within your text is to match the journal’s style and ensure you are consistent throughout the entire manuscript.

Have these suggestions been helpful? I welcome comments on this writing tip, as well as suggestions for future weekly writing tips.