
http://search.cpan.org/~mamawe/Algorithm-CheckDigits-0.38/

http://search.cpan.org/~tmtm/Business-Barcode-EAN13-1.01/lib/Business/Barcode/EAN13.pm

http://search.cpan.org/~mamawe/Algorithm-CheckDigits-0.38/CheckDigits/M11_008.pm
