How to make citations appear within square brackets [ ] instead of parentheses ( )?

Question

I'm using a this freely downloadable latex class file and the style is set to \bibliographystyle{ieeetr}. But when I cite something with \cite{} I get it inside ().

For example I get it as abc et al. (1) but what I want to get is abc et al. [1].

Please tell me how to get my citations inside [ ] ?

Answer 1

You can simply say

\setcitestyle{square}

in your document preamble (see natbib documentation, section 2.9).

However, if you're using the class for a submission to an IEEE conference, leave as they want.

Answer 2

The reason why you are getting citation numbers inside parentheses instead of square brackets is that in the class file you use, the package natbib is loaded with the option round, see line 51:

\usepackage[round, sort, numbers]{natbib}

Just replace this line with

\usepackage[sort, numbers]{natbib}

save your class file, compile your .tex file and you should get square brackets. Alternatively, simply adding \setcitestyle{square} in the preamble of your document without modifying the class file itself should work.

Note, however, that you may also have to edit the bibliographic style to change the style of the bibliographic number (at present, is it enclosed by parentheses or square brackets?) for each item in the Bibliography section.

Answer 3

To complement egreg's answer, class files (like for the journal Annual Review) can set the open and close characters at \begin{document}. In that case, \setcitestyle{square} only works if it comes after \begin{document}.

Answer 4

This works for me:

\usepackage{natbib}
\setcitestyle{numbers}
\setcitestyle{square}

Output:

[x]

x denotes the number of the reference.