How to format your references using the Proceedings of the National Academy of Sciences of the United States of America citation style

This is a short guide how to format citations and the bibliography in a manuscript for Proceedings of the National Academy of Sciences of the United States of America (PNAS). For a complete guide how to prepare your manuscript refer to the journal's instructions to authors.

Using reference management software

Typically you don't format your citations and bibliography by hand. The easiest way is to use a reference manager:

Paperpile	The citation style is built in and you can choose it in Settings > Citation Style or Paperpile > Citation Style in Google Docs.
EndNote	Find the style here: output styles overview
Mendeley, Zotero, Papers, and others	The style is either built in or you can download a CSL file that is supported by most references management programs.
BibTeX	BibTeX syles are usually part of a LaTeX template. Check the instructions to authors if the publisher offers a LaTeX template for this journal.

Journal articles

Those examples are references to articles in scholarly journals and how they are supposed to appear in your bibliography.

Not all journals organize their published articles in volumes and issues, so these fields are optional. Some electronic journals do not provide a page range, but instead list an article identifier. In a case like this it's safe to use the article identifier instead of the page range.

A journal article with 1 author

R. D. Launius, Neil Armstrong (1930-2012). Nature 489, 368 (2012).

A journal article with 2 authors

Q.-Z. Yin, S. B. Jacobsen, Geochemistry: does U-Pb date Earth’s core formation? Nature 444, E1; discussion E2-3 (2006).

A journal article with 3 authors

M. H. Nielsen, S. Aloni, J. J. De Yoreo, In situ TEM imaging of CaCO₃ nucleation reveals coexistence of direct and indirect pathways. Science 345, 1158–1162 (2014).

A journal article with 6 or more authors

L. Khriachtchev, M. Pettersson, N. Runeberg, J. Lundell, M. Rasanen, A stable argon compound. Nature 406, 874–876 (2000).

Books and book chapters

Here are examples of references for authored and edited books as well as book chapters.

An authored book

D. Parker, International Valuation Standards (John Wiley & Sons, Ltd, 2016).

An edited book

M. Broy, I. H. Krüger, M. Meisinger, Eds., Model-Driven Development of Reliable Automotive Services: Second Automotive Software Workshop, ASWSD 2006, San Diego, CA, USA, March 15-17, 2006, Revised Selected Papers (Springer, 2008).

A chapter in an edited book

B. Zielosko, “Sequential Optimization of $$\gamma $$ -Decision Rules Relative to Length, Coverage and Number of Misclassifications” in Transactions on Rough Sets XIX, Lecture Notes in Computer Science., J. F. Peters, A. Skowron, D. Ślȩzak, H. S. Nguyen, J. G. Bazan, Eds. (Springer, 2015), pp. 65–82.

Web sites

Sometimes references to web sites should appear directly in the text rather than in the bibliography. Refer to the Instructions to authors for Proceedings of the National Academy of Sciences of the United States of America.

Blog post

T. Hale, This Cricket Was Infested By “Mind Controlling” Worms. IFLScience (2016). Available at: https://www.iflscience.com/plants-and-animals/this-bug-was-infested-by-mind-controlling-worms/ [Accessed 30 October 2018].

Reports

This example shows the general structure used for government reports, technical reports, and scientific reports. If you can't locate the report number then it might be better to cite the report as a book. For reports it is usually not individual people that are credited as authors, but a governmental department or agency like "U. S. Food and Drug Administration" or "National Cancer Institute".

Government report

Government Accountability Office, “Highway Infrastructure: Stakeholders’ Views on Time to Conduct Environmental Reviews of Highway Projects” (U.S. Government Printing Office, 2003).

Theses and dissertations

Theses including Ph.D. dissertations, Master's theses or Bachelor theses follow the basic format outlined below.

Doctoral dissertation

M. Battaglia, “Presenting a pluralized past: Assessing the efficacy of multivocal, bison-themed lesson units as a public education and outreach strategy for archaeology,” University of Arizona, Tucson, AZ. (2015).

News paper articles

Unlike scholarly journals, news papers do not usually have a volume and issue number. Instead, the full date and page number is required for a correct reference.

New York Times article

J. Kanter, Head of European Council Reappointed Over Protest. New York Times A10 (2017).

In-text citations

References should be cited in the text by sequential numbers in parentheses:

This sentence cites one reference (1).
This sentence cites two references (1, 2).
This sentence cites four references (1–4).

About the journal

Full journal title	Proceedings of the National Academy of Sciences of the United States of America
Abbreviation	Proc. Natl. Acad. Sci. U. S. A.
ISSN (print)	0027-8424
ISSN (online)	1091-6490
Scope	Multidisciplinary