$VAR1 = bless( [
                 'Book 1 author 1',
                 'Book 1 author 2',
                 'Book 1 title',
                 'Book1ISBN'
               ], 'XML::LibXML::NodeList' );

$VAR1 = bless( [
                 'Book 2 author 1',
                 'Book 2 author 2',
                 'Book 2 title',
                 'Book2ISBN'
               ], 'XML::LibXML::NodeList' );