# Add colon after volume + number

I am using biblatex for this. I would like to change the comma to a colon after vol (num) in articles. Currently, the format is:

Beth, T. and Gollmann, D. (1989). Algorithm Engineering for Public Key Algorithm. IEEE Journal on selected areas in communications 7 (4), 458–465.

And I would like to have (without affecting others, such as inbook):

Beth, T. and Gollmann, D. (1989). Algorithm Engineering for Public Key Algorithm. IEEE Journal on selected areas in communications 7 (4): 458–465.

What I have done so far is:

``````\usepackage[
refsection=chapter,
firstinits=true,
useprefix=true,
isbn=false,
doi=false,
mincitenames=1,
maxcitenames=2,
minbibnames=3,
maxbibnames=5,
style=authoryear,
dashed=false,
backend=bibtex
]{biblatex}
\DeclareNameAlias{sortname}{last-first}
\DeclareFieldFormat[article,inbook,incollection,inproceedings,patent,thesis,unpublished]{title}{#1}
\DeclareFieldFormat[article]{volume}{\textbf{#1}}
\DeclareFieldFormat[article]{number}{\textbf{\mkbibparens{#1}}}
\renewbibmacro*{volume+number+eid}{
\printfield{volume}
\printfield{number}
\printfield{eid}
}
``````

• Have a look at this, if you only want this for articles, go with `\renewcommand*{\bibpagespunct}{\ifentrytype{article}{\addcolon\space}{\addcomma\space}}`. – moewe Feb 27 '15 at 17:02