PNAS reference format

What PNAS expects

• Reference style: PNAS style, numbered in the order references appear in the text. Each entry includes the full article title.
• Authors: If there are more than five authors, list the first author's name followed by et al.
• Journal names: MEDLINE/PubMed abbreviations, or the full title for journals not indexed in MEDLINE.
• BibTeX style: pnas-new.bst, “the current PNAS bibliography style”.
• Templates: Word and LaTeX templates for research articles, Brief Reports and the SI Appendix. The LaTeX templates are on Overleaf.
• Length: The preferred length of a Research Report is 6 pages, with a maximum of 12. A standard 6-page article is about 4,000 words, 50 references and 4 medium-size figures or tables.

Setting up the bibliography

In the PNAS template, the bibliography style is:

\bibliographystyle{pnas-new}
\bibliography{refs}

PNAS also suggests the Automatic Journal Title Abbreviation package in Overleaf, so references do not appear longer than they will in print. References cited only in the SI go in a separate list.

Three references in PNAS style

1. J. E. Hirsch, An index to quantify an individual's scientific research output. Proc. Natl. Acad. Sci. U.S.A. 102, 16569–16572 (2005). https://doi.org/10.1073/pnas.0507655102
2. F. Sanger, S. Nicklen, A. R. Coulson, DNA sequencing with chain-terminating inhibitors. Proc. Natl. Acad. Sci. U.S.A. 74, 5463–5467 (1977). https://doi.org/10.1073/pnas.74.12.5463
3. A. Subramanian et al., Gene set enrichment analysis: A knowledge-based approach for interpreting genome-wide expression profiles. Proc. Natl. Acad. Sci. U.S.A. 102, 15545–15550 (2005). https://doi.org/10.1073/pnas.0506580102

Three PNAS papers, formatted by hand from the examples in the PNAS submission guidelines. The third has 11 authors, so it is shortened to the first author and et al. Italic and bold are not shown, and the DOI links are added here for checking. Titles, authors, volumes and pages were checked against Crossref on 2026-10-01.

LaTeX template

PNAS links its Word and Overleaf templates from the submission guidelines. Support for the LaTeX templates is through Overleaf. We do not have a PNAS template page yet.

Common mistakes

• Listing six or more authors in full. Past five, PNAS gives the first author and et al.
• Leaving out article titles. PNAS asks for the full title of each cited article.
• One combined list for the main text and the SI. PNAS wants a separate citation list for references cited in the SI.
• Citing unpublished meeting abstracts or “data not shown”. Neither is permitted.
• Spelled-out journal names where a MEDLINE abbreviation exists.

Check your .bib file

• BibTeX Validator (free) checks a .bib file for syntax errors and missing required fields.
• Citation Generator (free) builds IEEE, APA, MLA and Chicago citations from entry fields, in your browser.
• Reference Converter (free) converts between BibTeX, RIS and EndNote. The same converter is below.