| name | citation-formatting |
| description | Use when formatting citations or bibliographies in a scientific document. Covers the four dominant styles (APA, Chicago author-date, IEEE, Vancouver), in-text citation patterns, and the pitfalls of each (page numbers, et al. thresholds, DOI inclusion, ordering of references). |
Citation formatting
Four styles cover most science writing:
| Style | Where used | In-text | Reference list order |
|---|
| APA 7 | Psychology, education, much of social science | Author-date: (Smith, 2023) | Alphabetical |
| Chicago author-date | Some humanities-adjacent science, biology variants | Author-date: (Smith 2023) (no comma) | Alphabetical |
| IEEE | Engineering, CS | Numbered: [1] | By order of first citation |
| Vancouver / AMA | Medicine, biomedical | Numbered: (1) or superscript¹ | By order of first citation |
When the journal isn't specified, default to APA 7 for social/life sciences, IEEE for engineering/CS, then adjust to journal style sheet on submission.
In-text patterns (APA 7)
- One author:
(Smith, 2023) or Smith (2023) showed...
- Two authors:
(Smith & Lee, 2023), always both names.
- Three or more:
(Smith et al., 2023), with et al. from the first citation, except where ambiguous.
- Same author, multiple works same year:
(Smith, 2023a, 2023b).
- Direct quote: include page:
(Smith, 2023, p. 47).
- Multiple sources: alphabetical, semicolons:
(Lee, 2022; Smith, 2023).
Reference entry examples (APA 7)
Journal article:
Smith, A. B., & Lee, C. (2023). Title of the article in sentence case.
Journal Name in Title Case, 47(3), 112–128. https://doi.org/10.xxxx/yyyy
Book:
Smith, A. B. (2023). Title of the book in sentence case. Publisher.
Chapter in edited book:
Smith, A. B. (2023). Chapter title. In C. Lee (Ed.), Book title (pp. 47–72).
Publisher.
Preprint:
Smith, A. B. (2023). Title of the preprint. arXiv. https://arxiv.org/abs/2301.xxxxx
IEEE essentials
In-text: [1], [2, 5], [3]–[7]. Cited in order of first appearance.
[1] A. B. Smith and C. Lee, "Title of paper," Journal Name, vol. 47, no. 3,
pp. 112–128, 2023, doi: 10.xxxx/yyyy.
Notes:
- Author initials before surname, comma-separated.
- Title in quotes, journal in italics.
- Numbered list in order of citation, not alphabetical.
Common errors
et al. threshold confusion. APA 7 uses et al. from the first citation when there are 3+ authors. (APA 6 said "first time, list all up to 5." Don't use APA 6 anymore.)- DOIs as URLs. Modern APA:
https://doi.org/10.xxxx/yyyy, not doi: prefix.
- Journal title case. APA: article title in sentence case, journal in Title Case. People reverse these.
- Initials vs full first names. Initials only.
Smith, A. B. not Smith, Aadarsh B..
- Mixed styles in one bibliography. Usually a sign of pasting from multiple sources without normalizing. Always pick one and convert.
Tooling pointer
For BibTeX users: use biblatex (modern) over natbib (legacy). Style is set with \usepackage[style=apa]{biblatex} or [style=ieee]. The biber backend handles unicode names correctly.
Related: [[imrad-structure]].
