my $cr = REST::Client::CrossRef->new(
    mailto        => 'd...h',
    spit_raw_data => 0,
    add_end_flag  => 1,
    json_path     => [ ['$..author[*].[family,given,affiliation]'], ],
    json_path_callback =>
        { '$..author[*].[family,given,affiliation]' => \&unfoldauthors4 },
);

sub unfoldauthors4 {
    my ($authors) = @_;
    my @all = @{$authors};
    print Dumper @all;
    my $authors_limit = 50;
    my $last          = $authors_limit - 1;
    my $size          = @all / 3;
    if ( $size > $authors_limit ) {
        @all = @all[ 0 .. $last * 3 ];
        $all[ $last * 3 - 1 ] .= " ...";
    }
    my @res;
    my $i;
    for ( $i = 0; $i <= $#all; $i += 3 ) {
        my $line =
              $all[$i] . ", "
            . $all[ $i + 1 ] . "; "
            . join( " ", map { $_->{name} } @{ $all[ $i + 2 ] } );
        push @res, $line;

    }
    return \@res;
}