Scientific Writing

# Citation Styles Guide

## Overview

Citation styles provide standardized formats for acknowledging sources in scientific writing. Different disciplines prefer different styles, and journals typically specify which style to use. The five most common citation styles in science are AMA, Vancouver, APA, Chicago, and IEEE.

## Choosing the Right Style

| Style | Primary Disciplines | In-Text Format |
|-------|-------------------|----------------|
| AMA | Medicine, health sciences | Superscript numbers¹ |
| Vancouver | Biomedical sciences | Numbers in brackets [1] |
| APA | Psychology, social sciences, education | Author-date (Smith, 2023) |
| Chicago | Humanities, history, some sciences | Notes-bibliography or author-date |
| IEEE | Engineering, computer science | Numbers in brackets [1] |
| ACS | Chemistry | Superscript numbers¹ or (1) |
| NLM | Life sciences, PubMed | Numbers in brackets [1] |

**Default recommendation**: When in doubt, check the journal's author guidelines. Most biomedical journals use Vancouver or AMA style.

## AMA Style (American Medical Association)

### Overview
- Used primarily in medical research
- Based on the *AMA Manual of Style* (11th edition, 2020)
- Numbered citations appearing as superscripts
- References listed numerically in order of appearance

### In-Text Citations

**Basic format**: Superscript numerals outside periods and commas, inside semicolons and colons.

**Examples:**
```
Several studies have demonstrated this effect.¹

The results were inconclusive,² although Smith et al³ reported otherwise.

These findings³⁻⁵ suggest a correlation.

One meta-analysis⁶ found significant heterogeneity; however, the pooled effect was significant.⁷
```

**Multiple citations**: Use commas or hyphens for ranges
```
Multiple studies¹,³,⁵⁻⁷ have confirmed this.
```

**Same source cited multiple times**: Use the same number throughout

### Reference List Format

**Journal Articles:**
```
1. Author AA, Author BB, Author CC. Title of article. Journal Name. Year;Volume(Issue):Page range. doi:xx.xxxx
```

**Example:**
```
1. Smith JD, Johnson AB, Williams CD. Effectiveness of cognitive behavioral therapy for anxiety disorders. JAMA Psychiatry. 2023;80(5):456-464. doi:10.1001/jamapsychiatry.2023.0123
```

**Books:**
```
2. Author AA. Book Title. Edition. Publisher; Year.
```

**Book Chapters:**
```
3. Chapter Author AA. Chapter title. In: Editor AA, Editor BB, eds. Book Title. Edition. Publisher; Year:Page range.
```

**Online Resources:**
```
4. Organization Name. Page title. Website name. Published date. Updated date. Accessed date. URL
```

### Special Cases

**More than 6 authors**: List first 3, then "et al"
```
Smith JD, Jones AB, Williams CD, et al.
```

**No author**: Begin with title

**Advance online publication**:
```
Published online Month Day, Year. doi:xx.xxxx
```

## Vancouver Style

### Overview
- Developed by the International Committee of Medical Journal Editors (ICMJE)
- Described in *Recommendations for the Conduct, Reporting, Editing, and Publication of Scholarly Work in Medical Journals*
- Also called "author-number style"
- Numbered citations in square brackets
- References listed numerically

### In-Text Citations

**Basic format**: Numbers in square brackets after the relevant text, before periods and commas.

**Examples:**
```
Several studies have shown this effect [1].

The results were inconclusive [2], although Smith et al [3] reported otherwise.

These findings [3-5] suggest a correlation.

Multiple studies [1,3,5-7] have confirmed this.
```

### Reference List Format

**Journal Articles:**
```
1. Author AA, Author BB, Author CC. Title of article. Journal Name. Year;Volume(Issue):Page range.
```

**Example:**
```
1. Smith JD, Johnson AB, Williams CD. Effectiveness of cognitive behavioral therapy for anxiety disorders. JAMA Psychiatry. 2023;80(5):456-464.
```

**Books:**
```
2. Author AA, Author BB. Book title. Edition. Place of publication: Publisher; Year.
```

**Book Chapters:**
``