Know which entry of bib file has not been used

Question

Is there a way of knowing if I left out any bibliography entry in a specific tex file from an specific bib file?

I am doing a kind of a literature review and every day I write a bit I find several papers to add. I generally add them and write about them in the moment, but it would be nice to make sure I haven't left any of them out.

Answer 1

Use grep or some other search tool, or use a number in order of reference bibliography style and put \nocite{*} at the end of the document then any "unused" references will appear at the end of your reference list with the highest numbers, coming after any real reference

Answer 2

You can use the checkcites script, which is available in every recent TeX distribution.

Here's an example file, save it as checktest.tex; usage of \jobname and filecontents* is just for making the example selfcontained, you'll use your own .bib file, of course.

\begin{filecontents*}{\jobname.bib}
@article{used,
  author={A. Uthor},
  title={Title},
  journal={Journal},
  year={2015},
}
@article{unused,
  author={W. Riter},
  title={Title},
  journal={Journal},
  year={2015},
}
\end{filecontents*}

\documentclass{article}
\begin{document}

\cite{used}

\cite{undefined}

\bibliographystyle{plain}
\bibliography{\jobname}

\end{document}

If you compile it and run

checkcites checktest

The terminal will output

checkcites.lua -- a reference checker script (v1.0i)
Copyright (c) 2012 Enrico Gregorio, Paulo Roberto Massa Cereda

I found 2 citation(s).
Great, there's only one 'bib' file. Let me check it.
I found 2 reference(s).

Unused reference(s) in your bibliography file(s): 1
- unused

Undefined reference(s) in your TeX file: 1
- undefined

So the unused entry has no corresponding \cite command in the file, while undefined has a \cite, but has no entry in the .bib file.