# Creating .bib file containing only the cited references of a bigger .bib file

Normally, LaTeX will only create references for the BibTeX entries cited in the text. Is there a way of extracting these entries into a different `.bib` file automatically? For example if I have a `.bib` file with two entries, and only one is cited in a particular text, I need a way of creating a new `.bib` file with just that reference.

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## migrated from stackoverflow.comJan 21 '12 at 14:42

With a TeX Live distribution (possibly also with MiKTeX) there is a `bibexport` program. Assuming your document is `myarticle.tex`, you have to compile it normally and then you call

``````bibexport -o extracted.bib myarticle.aux
``````

where `extracted.bib` is the name that you want to give to your new `.bib` file. Notice that you have to give the extension `.aux` (or no extension at all).

Then you have to change the name of the `.bib` file in your document, in order to use `extracted.bib`.

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+1 Nice tool. I didn't know it. – Marco Daniel Jan 21 '12 at 15:38
In MiKTeX 2.9 this tool is missing :-( – Kurt Feb 15 at 16:24
Although this falls outside of the scope of the question, perhaps a brief word about how this tool does not work with `biber`-driven bibliographies (or with `.bib` files that use `biblatex` fields such as `date` instead of `year`) is in order. – jon Feb 15 at 16:29
@jon `bibexport` uses BibTeX for doing its job. The manual tells how to add new fields (section 1.4). For `biblatex`/Biber compatibility the script should look not only for `\citation` commands in the `aux` file but also for `\abx@aux@cite`. – egreg Feb 15 at 16:42
@egreg -- Right. I was thinking more for people who look at your answer, but don't realize why `bibexport` isn't working for them; most of them are not going to be modifying `bibexport.sh`. Another problem that might arise is if you use non-standard entry types (from BibTeX's perspective). I use `@Collectio{<key>,...`, e.g., for essay collections; that comes through as `@{<key>,...`. – jon Feb 15 at 20:02