my %publications = $tree->look_down( _tag => 'span');

 open my $fh , "<", $tree->as_HTML;
 while (<$fh>)
 {
  my $author;
  next unless ($_ =~ /(?:span|li)/;
  $_ =~ /span/ ? $author =~ /\>(.+)\<\/span/ : push @publications{$author}, /li\>(.+)\<\/li/;
 }