- $oldbiblio->{isbn} =~ s/ |-|\.//g,
- $oldbiblio->{issn} =~ s/ |-|\.//g,
+ $oldbiblio->{isbn} =~ s/ |-|\.//g if $oldbiblio->{isbn};
+ # pad | and ( with spaces to allow line breaks in the HTML
+ $oldbiblio->{isbn} =~ s/\|/ \| /g if $oldbiblio->{isbn};
+ $oldbiblio->{isbn} =~ s/\(/ \(/g if $oldbiblio->{isbn};
+
+ $oldbiblio->{issn} =~ s/ |-|\.//g if $oldbiblio->{issn};
+ # pad | and ( with spaces to allow line breaks in the HTML
+ $oldbiblio->{issn} =~ s/\|/ \| /g if $oldbiblio->{issn};
+ $oldbiblio->{issn} =~ s/\(/ \(/g if $oldbiblio->{issn};