LibGuides: AMA Citation: References & In-Text Citation

References and In-Text Citation in AMA

AMA primarily handles references through superscript numerals in the text that point toward a numbered reference list. AMA style has some major differences from both parenthetical systems (like APA and MLA) and footnote/endnote systems (like Chicago).

Reference List Formatting

Ordering

AMA reference lists are numbered, not alphabetized. Sources are listed in the order they appear in the text. Each number in the list refers to one source only.

Indentation

Unlike many other styles, AMA reference lists do not use hanging indentation.

Nathan DM, Buse JB, Davidson MB, et al; American Diabetes Association; European Association for Study of Diabetes. Medical management of hyperglycemia in type 2 diabetes: a consensus algorithm for the initiation and adjustment of therapy. Diabetes Care. 2009;32(1):193-203. doi:10.2337/dc08-9025
Magkos F, Yannakoulia M, Chan JL, Mantzoros CS. Management of the metabolic syndrome and type 2 diabetes through lifestyle modification. Annu Rev Nutr. 2009;29:223-256. doi:10.1146/annurev-nutr-080508-141200

In-Text Citation Formatting

Styling and Placement

References are cited using superscript arabic numerals. These should be placed outside periods and commas, inside colons and semicolons.

Rodriguez¹ reported on the study.

According to Rodriguez and Smith,²

Rodriguez et al³ reported on the study.

This method has been endorsed by professional societies.^4,5

The derived data were as follows^6,7:

To cite multiple references at the same location in the text, use hyphens to join a closed series of references or commas without spaces to separate other parts.

The 2 largest studies^8,9 to date found . . .

Past scholarship^10-14 has demonstrated . . .

Avoid placing a citation following a number or measurement unit to avoid confusing it with an exponent. Consider revising your sentence if necessary to avoid confusion.

The 2 largest studies to date included 26² and 18³ patients.
The 2 largest studies to date included 26 patients² and 18 patients.³
The 2 largest studies^2,3 to date included 26 and 18 patients, respectively.

The largest legion found in the first study was 10 cm.²
The largest legion found in the first study² was 10 cm.

Numbering

Each superscript numeral is a refence to that same number in the reference list. So, ¹ refers to the first item in the reference list. This means that, unlike some endnote systems, superscript numbers are reused any time the corresponding reference list source is cited in the text.

As previously reported,^1,2,10-14

General Author Name Guidelines

Authors in Reference Lists

Number of Authors	Reference List Format
1 Author	Doe JF.
2 Authors	Doe JF, Roe JP III.
6 Authors	Doe JF, Roe JP III, Coe RT Jr, Loe JT Sr, Poe EA, van Voe AE.
>6 Authors	Doe JF, Roe JP III, Coe RT Jr, et al.
1 Author for or and a group	Doe JR; Laser ROP Study Group.
>6 Authors for or and a group	Doe JF, Roe JP III, Coe RT Jr, et al; Laser ROP Study Group.
Group	Laser ROP Study Group.

Authors in In-Text Citation

Use only author surnames for in-text citations.

Number of Authors	Citation Format
1 Author	Doe⁴
2 Authors	Doe and Roe⁵
>2 Authors	Doe et al⁶

Rephrase your sentence to avoid the possessive form et al's.

Doe et al's⁶ data support our findings.
The data in the study by Doe et al⁶ support our findings.