my %hash;
$hash{$_->{'type'}} {$_->{'name'}} = $_->{'reference'} for @$array;

#$hash{$_->{'type'}}{ $_->{'name'} }for @$array;

print "Results:\n";
for my $k1 (sort keys %hash) {
    print "    $k1:\n";
    for my $k2 (sort keys %{$hash{$k1}}) {
        print "        $k2\n";
    }
}