# natbib: comma-separated for \citenum and colon-separated for \citep

My little example is as follows:

    \documentclass{article}

\usepackage[round]{natbib}
\newcommand{\citea}[1]{[\citenum{#1}]}
%\setcitestyle{comma}

\begin{document}

or ref \citea{efron2004least,hastie2015statistical}

\bibliographystyle{unsrtnat}
%\nocite{*}
\bibliography{test}

\end{document}


where the test.bib contains

    @article{tibshirani1996regression,
title={Regression shrinkage and selection via the lasso},
author={Tibshirani, Robert},
journal={Journal of the Royal Statistical Society: Series B (Methodological)},
volume={58},
number={1},
pages={267--288},
year={1996},
publisher={Wiley Online Library}
}

@article{efron1996bootstrap,
title={Bootstrap confidence levels for phylogenetic trees},
author={Efron, Bradley and Halloran, Elizabeth and Holmes, Susan},
journal={Proceedings of the National Academy of Sciences},
volume={93},
number={23},
pages={13429--13429},
year={1996},
}

@article{efron2004least,
title={Least angle regression},
author={Efron, Bradley and Hastie, Trevor and Johnstone, Iain and Tibshirani, Robert},
journal={The Annals of Statistics},
volume={32},
number={2},
pages={407--499},
year={2004},
publisher={Institute of Mathematical Statistics}
}

@book{hastie2015statistical,
title={Statistical learning with sparsity: the lasso and generalizations},
author={Hastie, Trevor and Tibshirani, Robert and Wainwright, Martin},
year={2015},

I know that \setcitestyle{comma} can change the punctuation. However, I want keep the colon-separated way for \citep by default, and use the comma-separated way for \citea which is modified from \citenum.
• Is something stopping you from writing [\citenum{efron2004least},\citenum{hastie2015statistical}]? – Mico Nov 18 '19 at 15:48
• Incidentally, with your setup, the formatted bib entries will not be associated with numbers such as [1], [2], etc. Hence, your readers may find that citation call-outs of the form [3,4] are not all that helpful. (In fact, readers may find it to be the very opposite of helpful…) – Mico Nov 18 '19 at 15:51