How to order citations?

Question

Assume I have cited a certain article first, but then recite it later as follows

This work \cite{citation1} and that research \cite{citation2,citation1,citation3}

Using

\bibliographystyle{unsrt}
\bibliography{bibliography}

I get something like

This work [1] and that research [2,1,3]

Is it possible to automatically write the second citation in global reference order, that is, [1,2,3], independently of the order I write the arguments in \cite{}?

If not, is it possible to sort any multi-citation, like \cite{citation2,citation1,citation3}, by year of publication, if available?

Edit: I am using BibTeX

Answer 1

You have three options depending on what bibliography package you are or are not using. Since you mention the unsrt bibliography style, I'm assuming you're using the default citation functionality of LaTeX (i.e., no package).

Option 1

Load the cite package:

\usepackage{cite}
\bibliographystyle{unsrt}

...

\bibliography{your-bibfile}

The default option will be to both sort and compress references, so [2,1,3] will become [1-3]. If you don't want the compression use:

\usepackage[nocompress]{cite}
\bibliographystyle{unsrt}

...

\bibliography{your-bib-file}

Option 2

Load the natbib package, with the [numbers,sort&compress] options. For this you will need to use the unsrtnat bibliography style. If you don't need compression, just use sort instead of sort&compress as the sorting option.

\usepackage[sort&compress,numbers]{natbib}
\bibliographystyle{unsrtnat}

...

\bibliography{your-bib-file}

Option 3

Use biblatex and biber to process your bibliography:

\usepackage[style=numeric,sorting=none,sortcites=true]{biblatex}
\addbibresource{your-bib-file.bib}

...

\printbibliography

If you want compressed citations, use style=numeric-comp.