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 reference managers.
BibTeX	BibTeX styles 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

A. D. Redish, Addiction as a computational process gone awry. Science 306, 1944–1947 (2004).

A journal article with 2 authors

A. Vähärautio, J. Taipale, Cancer. Cancer by super-enhancer. Science 346, 1291–1292 (2014).

A journal article with 3 authors

B. Marte, A. Eccleston, D. Nath, Molecular cancer diagnostics. Nature 452, 547 (2008).

A journal article with 6 or more authors

R. Shechter, et al., Hypothalamic neuronal toll-like receptor 2 protects against age-induced obesity. Sci. Rep. 3, 1254 (2013).

Books and book chapters

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

An authored book

A. Kramer, B. Legeard, Model-Based Testing Essentials (John Wiley & Sons, Inc, 2016).

An edited book

D. J. Bell, S. L. Foster, E. J. Mash, Eds., Handbook of Behavioral and Emotional Problems in Girls (Springer US, 2005).

A chapter in an edited book

D. Jamet, N. Lafrenière, X. Provençal, “Generation of Digital Planes Using Generalized Continued-Fractions Algorithms” in Discrete Geometry for Computer Imagery: 19th IAPR International Conference, DGCI 2016, Nantes, France, April 18-20, 2016. Proceedings, Lecture Notes in Computer Science., N. Normand, J. Guédon, F. Autrusseau, Eds. (Springer International Publishing, 2016), pp. 45–56.

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

J. Davis, Earliest Evidence Of Creating Specific Dog Breeds Found In Arctic Russia. IFLScience (2017). Available at: https://www.iflscience.com/plants-and-animals/earliest-evidence-of-creating-specific-dog-breeds-found-in-arctic-russia/ [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, “Transportation Infrastructure: Better Tools Needed for Making Decisions on Using ISTEA Funds Flexibly” (U.S. Government Printing Office, 1993).

Theses and dissertations

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

Doctoral dissertation

B. Hill, “HIV-specific CD8 T-cell clonality, publicity and function under different vaccine modalities,” George Washington University, Washington, DC. (2010).

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

L. Greenhouse, Court to Weigh Disparities in Cocaine Laws. New York Times A15 (2007).

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