use Spreadsheet::ReadSXC qw(read_xml_string);

##</code><code>##

use Unicode::String qw(utf8);
print utf8(" '$cell_contents'")->as_string;

##</code><code>##

Rougequeue de Güldenstädt   =>     'Rougequeue de Güldenstädt'

##</code><code>##

Güldenstädt's Redstart   =>     'Güldenstädt's Redstart'