Is there a more recent bibliography style file (.bst) for PNAS?

Question

As per the PNAS author guidelines:

References should be cited in numerical order as they appear in text. Because tables and figures will be inserted in the text where first cited, references in these sections should be numbered accordingly. Include the full title for each cited article. All authors (unless there are more than five) should be named in the citation. If there are more than five, list the first author's name followed by et al. Provide volume and issue numbers for journal articles as applicable; provide DOI numbers if volume/issue numbers are not available. Provide inclusive page ranges for journal articles and book chapters. Provide date of access for online sources. Cite databases in the text or as footnotes.

Journal articles are cited as follows:

1. Neuhaus J-M, Sitcher L, Meins F, Jr, Boller T (1991) A short C-terminal sequence is necessary and sufficient for the targeting of chitinases to the plant vacuole. Proc Natl Acad Sci USA 88(22):10362-10366.

Because the journal only accepts .bbl files embedded within the main .tex file, they do not provide a bibliography style. But their bibliography style has changed over the years (use of colon to separate number/volume and page numbers, volume number not in bold etc.), and there doesn't seem to be any up-to-date bibliography style.

Google led me to this and this packages (first one was obsoleted by the second one), but they do not match the PNAS bibliography style.

Obviously, this is not the end of the world as I could fix the .bbl file manually, but I was wondering whether there is a more recent version. bibtex or biblatex solutions are both okay, as the .bbl will be added in the main .tex file anyway (correct me if I'm wrong on this one please).

Worst-case scenario, how much work would be required to modify the bibliography styles, given that I have never done any work on bibliography styles?

Answer 1

I'm not aware of a BibTeX style file for PNAS, but the Bibulous project does provide an easy way of customizing styles. For the style suggestions linked to by the OP, it took me only a few minutes to put together a complete style template to follow PNAS' requirements. Using the following main.bib database file

@ARTICLE{Neuhaus,
  author = {Jean-Marc Neuhaus and Liliane Sitcher and Meins, Jr, Frederick and Thomas Boller},
  year = {1991},
  title = {A short C-terminal sequence is necessary and sufficient for the targeting of chitinases to the plant vacuole},
  journal = {Proc Natl Acad Sci USA},
  volume = {88},
  number = {22},
  pages = {10362-10366}
}

@INCOLLECTION{Hill,
  author = {Adrian V. S. Hill},
  year = {1991},
  title = {HLA associations with malaria in Africa: some implications for MHC evolution},
  booktitle = {Molecular Evolution of the Major Histocompatibility Complex},
  editor = {Jan Klein and Dagmar Klein},
  publisher = {Springer},
  address = {Heidelberg},
  pages = {403-420}
}

and the style template file main.bst (the lines below show the complete file)

TEMPLATES:
article = <au> (<year>) <title>. \textit{<journal>} <volume>(<number>): [<startpage>--<endpage>|<startpage>|<eid>|].[ <note>]
incollection = <au> (<year>) <title>. \textit{<booktitle>}[, vol.~<volume>, ][, <edition_ordinal>~ed.][, <null.if_singular(editorlist, edmsg1, edmsg2)>~<ed>][, <series>][, Chap.~<chapter>] (<publisher>, <address>)[, pp~<startpage>--<endpage>|p~<startpage>|<eid>|].[ <note>]

SPECIAL-TEMPLATES:
authorlist = <author.to_namelist()>
editorlist = <editor.to_namelist()>
authorname.n = [<authorlist.n.prefix> ]<authorlist.n.last>[ <authorlist.n.first.initial()>][<authorlist.n.middle.initial().compress()>][, <authorlist.n.suffix>]
au = <authorname.0>, ..., <authorname.9>
editorname.n = [<editorlist.n.prefix> ]<editorlist.n.last>[ <editorlist.n.first.initial()>][<editorlist.n.middle.initial().compress()>][, <editorlist.n.suffix>]
ed = <editorname.0>, ..., <editorname.9>
null = {}

OPTIONS:
edmsg1 = ed
edmsg2 = eds

compiling the main.tex file

\documentclass{article}
\usepackage[paper=letterpaper, text={6.5in,9in},centering]{geometry}

\makeatletter %
   \renewcommand{\@biblabel}[1]{#1.}
\makeatother

\begin{document}
\nocite{Neuhaus,Hill}
\bibliography{temp}
\bibliographystyle{temp}
\end{document}

produces the following formatted result:

This provides templates for only journal articles and articles/chapters in books, but the PNAS website provides guidelines for only these two. Templates for other entry types are easily derived from the two shown here. (For example, a book entry type template can be defined by adding another line

book = <au> (<year>) <title>. ...

in the lines below TEMPLATE: in the style template file.)

Answer 2

Also check out https://github.com/jburon/pnas2011.bst for PNAS bibtex style updated to match the current fashion in reference layout as of 4 September 2011.

Answer 3

The link to pnas2011.bst posted above is broken. However, PNAS offers pnas-new.bst as part of their official latex templates at: http://www.pnas.org/page/authors/latex. It's their template file, so I don't expect them to complain about the result :).

Note that URLs must be cited via a note to conform to the suggested PNAS style (cf. http://www.citethisforme.com/guides/pnas/how-to-cite-a-website). E.g.:

@misc{NIST_air_refractive_index,
   Author = {Stone Jr., Jack A. and Zimmerman, Jay H.},
   Title = {Index of Refraction of Air, NIST publication},
   Publisher = {National Institute of Science and Technology},
   note = {Available at: \url{https://www.nist.gov/publications/index-refraction-air} [Accessed June 7, 2017]}, 
   Year = {2001} }

Answer 4

I found this in the PNAS site, so I guess it's the official bibliography style file.

http://www.pnas.org/site/misc/pnas2011.bst