pnas-citation

Reference Style (pnas-citation)

When to trigger

• References are in author–date (APA/Harvard) or another journal's style and must become PNAS style.
• The reference list is not ordered by citation appearance.
• Author lists are truncated with "et al." in the bibliography.
• In-text citations are not numeric.

PNAS citation mechanics

• Numbered, in order of appearance in the text, as numbers in parentheses: (1), (2, 3), (4–6).
• A single numbered reference list, numbered consecutively in the order references first appear in the text.
• The reference list gives full author lists (PNAS does not truncate to "et al." in the bibliography for typical author counts — confirm any cap for very long lists).
• Journal titles abbreviated (standard ISO/CASSI abbreviations); include volume, page or article number, and year.
• Each reference includes the article title.

This is PNAS's own numbered format. It resembles Science in being numbered-by-appearance, but follow the PNAS reference template for punctuation, ordering of elements, and abbreviation conventions — do not assume Science's exact formatting.

Reference formats (shape — confirm details in current PNAS guidelines)

• Journal article: 1. A. B. Author, C. D. Author, E. F. Author, Article title. J. Abbrev. Volume, page–page (Year).
• Book: 2. A. B. Author, Book Title (Publisher, ed. X, Year).
• Book chapter: 3. A. B. Author, Chapter title in Book Title, C. D. Editor, Ed. (Publisher, Year), pp. xx–yy.
• Dataset: 4. A. B. Author, Dataset title. Repository. Accession/DOI. Deposited DD Month Year.
• Preprint: 5. A. B. Author, Title. Repository [Preprint] (Year). DOI/identifier (accessed DD Month Year).

Initials precede surnames; article titles in sentence case; journal abbreviated. Use a reference-manager PNAS style file to enforce this mechanically, then do a manual pass.

Common conversion fixes

From	To (PNAS)
"(Smith et al., 2021)"	"(12)"
"Smith, J. (2021)."	"J. Smith, …"
Truncated "et al." in biblio	full author list
Alphabetical reference list	ordered by first appearance
In-text author–date everywhere	sequential numbers (1), (2), … in text

Worked conversion (author-date → PNAS numbered)

Source (APA, in text and list):

"Recent work (Smith & Lee, 2021; Okafor et al., 2022) shows …" Smith, J., & Lee, K. (2021). Title of the article. Journal Name, 12(3), 45–58.

PNAS:

"Recent work (1, 2) shows …" — where (1) is the first to appear in the text. 1. J. Smith, K. Lee, Title of the article. J. Name 12, 45–58 (2021).

Note the changes: in-text becomes sequential numbers in appearance order; initials lead surnames; the article title is kept; the journal is abbreviated and italic-by-convention; volume is given without the issue number; full author list (no "et al." in the bibliography).

Tooling

• Use Zotero/EndNote with the PNAS CSL/style; do a final manual pass on abbreviations and author-list completeness (managers often truncate).
• Verify every in-text number resolves and the list has no gaps/duplicates; renumber after any reordering of the text.

Output format

【Style detected】 author-date / other → PNAS numbered
【Numbering】 by appearance? single numbered list? yes/no
【Author lists】 full (not et al.) in biblio? yes/no
【Journal abbreviations】 applied? yes/no
【Element shapes】 article/book/chapter/dataset/preprint correct?
【Unresolved/duplicate refs】 [...]
【Next】 pnas-submission

Anti-patterns

• Do not leave author–date citations anywhere in a PNAS manuscript.
• Do not alphabetize the reference list — order is by appearance.
• Do not truncate author lists with "et al." in the bibliography.
• Do not assume Science's exact reference formatting — use the PNAS template.